This guide will help you get all the steam achievements for Fistful Of Frags in the most convenient way possible. Some achievements may require some cheesing.

This guide was made in June 2021, and might get outdated in the future batches or updates. If this is the case let me know and I'll update it.

A lot of achievements can be made easier by the use of console commands, for this you'll need to be able to open the console.

Go to settings>keyboard and bind open console to a easy to remember key.
Then go to settings>keyboard>advanced and tick of the enable console box.

Just press the key you binded to console in game and type in the command you need.

Your first kill among other human players
Join any server with a person on it and kill them, easiest achievement of your life.

kill some enemies severely injured by another player, while that player is still close to the victim
Simply follow a teammate around, most players you'll meet are on their own so when you both open fire one of you will be seen as the Frag Robber to the game.

Make headshots with a bow from long range
This can be quite tricky to pull off in online games but far from impossible with some practise, find a good long range spot and fire away.
A cheesy method is to get this achievement is to start a game with bots and typing fof_bot_stop_1 in the console, this will freeze the bots in place and stop them from shooting. Line up a shot from a long range and repeat until you have the achievement.

Drop 15 enemy player's hat by shooting over their heads
works the same as robin hood but you can use any weapon and you have to make a hatshot instead of a headshot. It's quite easy to tell when the hat drops so just keep on aiming high until you get the achievement.

Kick some enemies into water, fire or a large fall
For this you need to bind kick to something easy to use and find a cliff or fall in a map. Some quick maneuvering should trick most players and bots to stand between you and the cliff. The boots upgrade should also help you out since it increases knockback.

Kill some enemies while being under whiskey's effect
Find a way to damage yourself, either by falling off something or by being shot. After you have been damaged you can drink some whiskey to get the drunk effect. Then it's a case of getting kills before the effect wears off. this works best in full servers where it's easier to quickly find an opponent.

pick lit dynamite sticks thrown by other players
This can be very difficult in online games since a lot of players don't use dynamite or cook it before they throw. The best way to get this achievement is by playing the dynamite everywhere challange in singleplayer. Simply defuse the sticks thrown at you before they explode.

Kill a few steam freinds with bare hands
Kill someone from your steam friendslist with your fists over and over until you get the achievement. The game is free and only a short download, so this might be a time to get someone to play with you. Alternativlty you can find someone in the fistful of frags community to help you out.

Get some frags while your health is lower than 15HP
This one is pretty easy since a simple duel will often result in you killing someone with less than 15HP.
If you're having trouble with it then here are 2 very easy ways of getting it:

Online
find a server with not too many people on
get yourself a pretty good weapon, preferrably something that can oneshot an opponent
jump of something tall to get yourself down to 15HP
get as many kills as you can until you either die or drink whiskey to get yourself above 15HP again
repeat until you have the achievement

Offline
start an offline game with bots
type in fof_bot_stop_1
jump off something high until you are 15HP
kill the frozen bots until you have the achievement

Get some kills with explosive chain reaction effect (their own dynamite kills them)
Possibly the most difficult achievement to get in online games since they have to hold their dynamite or stand next to their it while your dynamite explodes without killing them directly. You can do this with a friend in an empty server but the easiest way is to do the dynamite everywhere challenge. This still might take a while but it has a much better chance of exploding one of the sticks before their thrown is still much better than trying it in multiplayer.

Kill enemies ending their streak of 7 or more kills
This will be achieved eventually when playing online, but it requires that someone in the server is dominating the game. An easier way might be to have a friend help you in an empty game. If you don't have someone that can help you, use an offline game with a bot.

Get some kills shooting lit dynamite
This doesn't have to be your own dynamite, any dynamite one the ground will do. This works best on full servers by throwing it in crowded area's or in the middle of a fight between 2 people, and shooting it before it can explode on it's own. This makes for some hilarious moments but if you're having difficulties with it you can always do it with bots and the console command fof_bot_stop_1.

Kill enemies while reaching 100% overweight due weapon accumulation
Pick up or buy all the weapons you can until the game tells you you are overweighted, then kill any opponent until you have the achievement. The most difficult thing about this achievement is not getting killed before you are overweighted.

Kill enemies with dual Colt Walkers
Colt Walkers can be found in a gold crate. Buy 2 of them and equip one in each hand, then kill a bunch of opponents.
Gold crates have a long cooldown so try to lay low while you're waiting for the cooldown to end, this works best in not too populated servers or with bots.

complete X amount of games
There are 3 of these:
Rancher: complete 25 games
Gunfighter: complete 100 games
Legend: complete 500 games

Legend will most likely be the last achievement you need to unlock since the average game takes 10 minutes, meaning you need atleast 83 hours of playtime. There is a way to cheese this so completing 100 games takes 17 minutes instead of 17 hours.
start a game with bots that has a round time of atleast 10 minutes.
join a team
put the following commands in the console:
sv_cheats 1
fof_bot_stop_1 (not neccesary but recommended)
fof_sv_obj_warmuptime 0
host _framerate 1

This will make rounds go by super quickly. You'll still need to join a team before the timer is up for it to count though, so make sure to press space a few seconds before the timer hits 0. There might be a quicker way to do it but this is what worked for me.

9/6/2021:
-added hat-shooter achievement
-added how to open console part (thx to Shiny Espeon for input)

After following this guide you should have 100% of the achievements on Fistful of Frags.
Any questions, suggestions or snake lore is welcome in the comments.