By far the most time-consuming part of getting 100% achievements is winning with every deck on every difficulty. That's 95 wins! The only real way to speed it up is to improve your winrate, so here are my tips. According to my stats I've won 107/273 runs.

• D&DG is not Blackjack. You don't win the same way you'd win in Blackjack. In Blackjack, having a deck of only 7's would mean you probably never lose, while in D&DG it'll do really well... until you go up against an opponent that can reduce your limit to 20, and that's where you'll lose your run.
  
• Most good cards have positive effects when you play them, so if you play as many cards as possible, you'll greatly increase your chance of winning. That's why my go-to strategy is to have as many low score cards (and negatives) as possible in my deck. In the first floor, the Tavern, you have 4 events that help you shape your deck this way: Have a drink, Stay a Night, Card Remover, Counterfeiter. The first 3 help you remove cards, and Counterfeiter let's you change the values of your numbered cards. I'll typically use these to get rid of as many Face cards as a I can, and lower values of the 6, 7, and 8's to 4 or 5 (depending on what I can afford). Don't worry about saving chips for future floors, you get plenty, and by far the best ways to spend them are all on the first floor. Note that some starting decks have even worse starting cards than Face cards, like the 5 of Wands or Cardecu, remove these first.
  
• Besides letting you remove a card, the Have a drink event in the Tavern gives you Loyalty card, which is a way for any deck to heal even without Heart cards. Fantastic. Whenever you play it and have some spare Advantage, dump some in there. Then when it shows up while your score is low and you have enough Advantage to fully fill it, do so to heal. This often lets you heal 15+ HP every couple of fights.
  
• That brings me to Advantage. My favorite Chip is the one that gives you 1 Adv per card played when you win with max score (note that "Winning" with max score also means you need to have a higher value than your opponent). With my strategy of many low score cards this can often give you 10+ Advantage for a single won round. Second best is the one that gives 1 Adv when you hit with a Score over 12, for similar reason. In general when evaluating Chips, try to go for ones that you can reliably trigger (ideally multiple times per round) regardless of what you opponent does. Getting 1 per won round sucks when you're up against a deck that can reliably get max score (a draw is not a win), and getting 1 when standing before your opponent sucks against the many decks that will only hit once or twice on average.
  
• Chips are bountiful after the first floor, so almost always pay to see the 4th card after a battle.
  
• Did you know you can exploit enemy cards? Obviously not good with every exploit card, but finishing them off with their own Calamari Game Card is fantastic.

• After the Tavern floor you'll need to pick a path, and the Good Path is almost always easier. In general the bosses on the Evil path are more punishing, especially the 4th floor has some horrible encounters (Executioneer & Surrounded come to mind). But there is one amazing thing on Evil Path: Roulette (3rd floor). If you're not unlucky and have a bit of cash you can set all your numbered cards to be a low (and predictable) score. Usually this isn't worth it for the harder path, but for large starter decks (Red Deck, Black Deck, Full Deck) I would still try it. With a Full Deck, setting all 36 of your numbered cards to be 1 of Hearts is run winning. And with a bit of luck, you'll find a Secret Passage event to get to Good Path after you use it.
  
• There's not that many events in the game, so it's not too hard to predict what you'll get. I think on average each event has like a 75% chance to show up on it's floor, so if you're looking for anything specific you'll find it most of the time.
  
• The only cards in the game that punishes a deck full of low-score cards are Rorschach and RSVP. RSVP doesn't matter too much, as 8 damage is easily tankable and there are no opponents that are build around it. There is 1 opponent who uses Rorschach, and that's the Psychologist (Head Office, Good path Floor 4). Avoid it at all costs, this will almost certainly kill your run (especially on difficulty 4 or 5). Luckily, all the other encounters on this floor are fine. Marketing, Taxes, and Layoffs can be annoying but certainly pick any of them over Psychologist.
  
• Something that took me way too long to figure out was that after you see your first set of Tarot Cards, you can predict your second and third sets; the cards leftover after your first pick will be flipped for your second pick. So during your first pick it's usually worth figuring out what your future options will be, and sometimes you can even build towards them. On All-in Difficulty the final boss will take both the regular and upside-down version of the last remaining card, making it absolutely vital to pick the upside-down Fool when you see it; if the final boss gets the regular Fool card the fight is nearly impossible to win (and you don't want to pick regular Fool yourself either, it's the worst card in the game).

• While this game is not Blackjack, getting max score is still very valuable. Since you'll ideally work towards a deck where the maximum value of a card is ~4, you'll almost always get a score of 17 or above. That's where Round Up and Flexible cards come in. I'll almost never skip an Ace or Half card, and with enough Half's you'll almost always get max score (while rarely busting). Some Handy cards are also great for this, like the Official Trump Card, Ace in the Hole, Get Out of Jail Free Card, Wild Card, and Trump Card. (Note that it shreds on discard, but if you win the enounter with it, it doesn't discard; use this as your finisher! Do try to wait for your opponent to stand, so you can be sure they'll die from it.)
  
• Disrupting your opponent is often even more valuable than getting max score. Lucky for us, most of the cards good at this have a low score: Gerald, Break Limits, +2, Rules Card, Sweep the Leg, Yellow Card. Having at least 1 or 2 burns in your deck helps against opponents relying on specific (locked) cards.
  
• The single best card in the game is Terminate the Tower, and nothing else is even close. In most games, any effect that lets you pick between a couple options, will have options weaker than regular effects because you pay for that flexibility, but TtT lets you pick between 4 of the best cards in the game. Break Limits can often let you bust your opponent, Sweep the Leg will give you a huge advantage in this and future rounds, Scratch is great as a finisher or for scaling in long fights, and Expulsion can be dangerous, but TtT allows you to only pick it when you know you're already winning the round. Seriously, this thing is insane.
  
• A great common combo is King of the Hill + Throwing Card. KotH is almost always my only Face Card, and because our deck is full of low-score cards it pops up often, guaranteeing Blackjacks. It's Spades so we'll build up a bunch of shield, keeping us healthy and making Throwing Card do huge damage. Throwing Card is a guaranteed pick up from the Card Printer event on the 4th floor on the Good Path, so you'll often have access to it. Do beware that cards in your hand can also block King of the Hill (making Booster Pack a lot weaker).

Go Good Path, get rid of high score cards, get low score cards that are flexible or disrupt your opponent, and you'll breeze through the game. Never click Psychologist fight.

The following achievements will be gained by winning with all decks on All-in difficulty:

• Managed It
  
• Jackpot
  
• Doubled Down
  
• Tripled Down
  
• Quadrupled Down
  
• Lorded Over
  
• Went ALL IN!
  
• That's My Lucky Number
  
• Decked Out
  
• Highly Deck-orated

Winning at least once with both good and evil path also gives you all the boss achievements:

• Bounced Back
  
• A+
  
• Famous for Being Famous
  
• Bossed Around
  
• Like a Boss
  
• A Dungeon & a Dracon
  
• Hopeful
  
• Despairing

Note that the final boss from All-In difficulty is the same on good and evil path, so you don't need to do both paths at All-In difficulty, you can simply do it at difficulty 1.

I reccommend not bothering with this until after you've got Highly Deck-orated as you'll get most along the way. The only exception is to keep an eye out for Foils.

Note that Foil cards also count as cards you "win" with, even if you literally never play them. I hate the 21 of Suit cards, but if I saw them as Foils I would just pick them up to get the win with them.

The best event for collecting regular cards you may just have missed is Slot Machine. Do regular runs on easy difficulty, saving up loads of chips (Diamond cards, Temperance, and Calamari Game Card are best for this), and just keep spinning the slot machine searching for cards you're missing. No other event in the game just lets you search for specific cards.

Not every card can be collected in the regular way.

• 0's, -1's, -11's can only be created from the Counterfeiter in the Tavern. -11's are the most annoying (I was still missing all 4 after I got my All-In wins), but my best strategy was to start with a regular/signature deck of the Suit I'm looking for, and not spend any chips at the start. If you go into the Counterfeiter with 429 chips, that's enough to change a 2 to a -11. That's a pretty reasonable amount to get in the Tavern if you don't spend many.
  
• 1's can either be made by the Counterfeiter, or starting with the Giant Rat deck.
  
• 1 and 11 of Nothings can also only be gotten through to Counterfeiter. Easy when starting with Deck of Nothings.
  
• Face cards and Aces of Nothings are only available from the Deck of Nothings.
  
• 5 of Wands, Cups, Pentacles, and Swords are starting cards in the Signature Suit decks. The random cards added into your deck from difficulty 3 on do not count.

I'm pretty sure there's a hidden mechanic in the game where you'll always have at least 1 Tarot Card available that you need a win with, so if you're only missing 1 or 2 you'll always encounter them.

After getting my All-In wins there were like 4 Tarot Cards I'd never won with (regular Justice and Fool, and upside-down Hermit and Strength). 3 of these were easy since you're very experienced with the game at this point and probably playing on difficulty 1, but the Fool took me a few tries (hence why I called it the worst card in the game before). My ultimate solution was to start Giant Rat deck and get 2 Kanban's and 2 Cue Cards, making it quite likely I could move the Fool to my hand. Getting Club of 4's, 2 Cue Cards, and a deck with a total score of under 21 also allowed me to kill most opponents on the first round (by having the Cue Cards target each other, dealing 4 damage each time).

Get a blackjack then hit and bust

After getting blackjack just keep pressing hit until you bust.

Have at least 21 Advantage

With the Chip that gets you one per played card on a max-score win, and my strategy of many low-score cards, you'll get this soon enough. Alternate strategies are the Interact Chips and just pay with health or chips. Could be combined with Fidget Flipper.

Win a round with blackjack 121 times

You'll almost certainly get this while going for all All-In wins (I have 6777 after getting 100% achievements).

Win a round with a score of 5

Dog event in Casino (3rd floor, evil path) stands on 2, so easy to get there. Another option is to burn your opponents entire deck; the Bouncer boss (2nd floor, good path) only has 3 cards so not that hard.

Get a blackjack with three played cards worth 7

Just fill your deck with as many 7's as you can. Counterfeiter event in the Tavern is useful. Misprinted Card rounds up to 7 and gives you a 7 in your hand, so you'd only need 1 more.

Win with a blackjack while all your played cards are locked

Card Sleeve and can help you lock cards, especially if it's Foil (or get it into your hand with a Kanban card). Same for either version of the Tower Tarot. Cards that round up (Half, Pi, Birthday Card, Jack and the Beanstalk) will eventually get you there. Can also play and lock cards that give you instant blackjack (King of the Hill, Loyalty Card, Trump Card), but note that they only give blackjack on play; if you already had a non-zero score when you played them, their value is probably not 21. I'd recommend doing it with Half or Pi, as that also gives the Very Round achievement.

Deal at least 100 damage in one hit

Multipliers (Expulsion, Devil Tarot) help a lot, especially when stacked. Terminate the Tower card lets you get multiple Explusions in your deck, and it's Break Limits option makes it easier to bust opponents. Building up shield (King of the Hill, Report Card, Spades) combined with a Throwing Card and some multipliers can deal insane damage (I've seen it go over 2000). If using that strategy can also go for Shields in Spades.

Have at least 100 shield

King of the Hill, Report Card, Spades cards are all great for this. If you combine it with Throwing Card it can get you Heavy Hitter.

As an alternative, start with the Giant Rat deck, make sure your total deck score remains under 21, and try to find a Spade of 5's. Have the Cue Cards infinitely target each other to build up infinite shield.

Get a perfect Memory Test

Just pure luck. Memory Test event shows up in the Lounge (2nd floor, good path).

Win with a deck with at least 52 cards

Adding in many low-score cards makes big decks still strong enough to win. The Full Deck starter deck starts with 54 cards, and using the Roulette event (Casino, 3rd floor, evil path) can make the numbered ones harmless. Alternatively, the event that lets you add the most cards is Slot Machine (3 cards per 99 chips) but they're random cards so it might be hard to win.

Use a Card Sleeve on an Old Baseball Card

"Completing" a Baseball Card adds both of these to your deck. Even better if you get a Foil Card Sleeve (or move it to your hand with Kanban).

Sell a Chipcoin for at least 500 chips

Another pure luck one, though it's quite often that the event goes above 500. The Crypto Bro event is located in the Basement (2nd floor, evil route). Requires 150 chips to play.

Win a run where you finish with none of the cards from your starting deck

Easiest on some of the later starter decks that are very small. I got it with the Birthday deck. Can potentially be combined with Tiny Deck.

Die to your own Cardiovascular Exercise

This was actually the final achievement I needed, despite almost always picking Cardiovascular Exercise when I saw it. My final strategy was to use the Chili Chip that lets you take 3 damage for an Advantage. If you have that, just play until Cardiovascular Exercise is the final card in your deck, use the Chip to go down to 1 or 2 HP, and hit. (Beware that if you start from a health total divisible by 3, you can't do this.)

Win a run without using Advantage

Just get cards that don't rely on Exploit and Handy. Might take a couple of tries, but there's plenty of good cards that don't use Advantage.

Exploit Double Back Cards at least 21 times

Not sure if this has to be done in 1 round, 1 game, or just overall. I did it all in 1 round with the Chip that lets you interact with it for Advantage. Can be combined with Advantageous.

Have over 10000 chips

10k is a lot, even with a good Diamond deck and a couple Calamari Game Cards you're unlikely to get here naturally. The card you'll need is Time Card, and exploit it a lot. Best done with the Chip and a Chair Chip, that gives you infinite advantage when you're under a HP threshold. Theoretically can also be done with the Chip that lets you pay chips for Advantage, 4 copies of Time Card, and Fingerprint Card.
Note that it doesn't need to be your Time Card; the Janitor in the Tavern (1st floor) has it.
Alternative strategy, similar to what I described for Shields in Spades, get 2 Cue Cards (from Giant Rat deck), the Diamond of 6's, and a deck with a total score between 15 and 21, then use the Cue Cards on each other for infinite money.

Win with a deck with 5 cards or fewer

Play Wizard Deck and look for round-up cards early, especially Pi of Hearts/Spades. If you find a King of the Hill you don't even need Memory Card, and that can also work with the Fortune Teller or Birthday Deck. The main danger is your KotH or Memory Card getting burned. Judgement is the best Tarot Card countermeasure for that. A Booster Pack can also work as a backup, though it will block your KotH so better with Memory Card. Another option is to try and get 2 Cue Cards, Club of 4's, and 2 cards with a combined score of at least 13, then burn down your opponent in the first round by infinitely looping your Cue Cards, but that's hard to set up. This is one of the hardest achievement in the game, so might take you some tries.

Have a Half or Pi Card Round Up to have a value of exactly 21

Best combined with Locked In. Lock them with Card Sleeve or the Tower Tarot.

That's pretty much all the tips I've found over ~140 hours of gameplay. This game is great, and I was surpised there aren't many resources out there to help win and hunt down achievements. Hope my tips helped you in that regard, and happy gambling!