DAI is no a good game for mods. Fortunately, community has some good mod managers. There are two, DAI mod manager and FrostyModManager.

• DAI mod manager is abandoned but there are still many people use it.
  
• FrostyModManager is the new one and is still in development. And it support mod created for DAI mod Manager.

For this recommendation, I choose FrostyModManager only. Here is the downloadlink.
FrostyModManager[github.com]
Choose the mod manager not the editor.

This tool is fairly easy to use.
Here is the vedio installation and usage guide.
How To Install Frosty Mods[imgur.com]

Written Guide:

• Download and install Frosty Mod Manager.
  
• Install required softwares from Mod Manager’s “prereqs” folder.
  
• Launch Frosty Mod Manager, then select DragonAgeInquisition.exe inside your game directory
  
• [Optional]For anyone struggling to open FrostyModManager. Right click on the icon and select run as an administrator. To avoid having to do this every time, go into properties and find "Run as an administrator" and make sure it is selected
  
• Click the Import Mod(s) button, then select the mod file(s) you want to import
  
• Select the mods you want to enable in the left area and click Apply Mods or double click them to activate them (you can change the order of the mods as you need in the right area)
  
• Make sure the mods you want on are checkmarked on the right side
  
• Click Launch
  
• You have to launch the game through Frosty Mod Manager's Launch button every time though. If you launch the game directly, the mods would not be enabled.

Also there is a QA for trouble in the official forums for Frosty.
trouble guide[forums.nexusmods.com]

Speed Launch[www.nexusmods.com]
Boot the game faster than ever, and with benefits!
- Completely skip the BioWare Logo movie
- Completely skip the Save Reminder screen
- Autologin; You do not need to press start ever again!
- Offline mode; If you go offline on Origin, you'll still be able to quickly access your saved games!
- Developer launcher; A "jump to map" feature that allows you to quickly launch any playable level in the game!

Bugs Be Gone[www.nexusmods.com]
Aims to rid Inquisition of its lingering issues and bugs.
2020-11-13: The Frosty version seems to have issues right now. If you're using Frosty Mod Manager, use it to import the .DAIMOD file instead.

Fonty[www.nexusmods.com]
Changes the Copperplate block font to something more readable, such as Time New Roman which is my favorite. Essential quality of life mod.

Quicker Looting[www.nexusmods.com]
This mod disables the looting animations, so you don't have to bend over again and again. Save you tons of time!

No More Fog of War[www.nexusmods.com]
After multiple playthroughs, players got tired of having to clear away the fog of war. So... maps are now always clear of it!
This mod turns the fog of war completely off for the maps modified. If you uninstall it, maps will revert back to their pre-mod appearance.
Choose the FBMOD version, not the DAIMOD version, since we will use Frosty mod manager not DAI mod manager. The same principle should be used for other mods.

Configurable Increased Inventory Capacity[www.nexusmods.com]

• Tired of running back to a shop every 15 minutes while exploring the Hinterlands? (More like 5)
  
• Wish you could headcanon the use of The Iron Bull as a personal pack mule? (Shale is one true pack mule)
  
• Want to pretend like your Mark is actually a Bag of Holding embedded in your hand? (Maybe spirits mimic your stuff?)

Well, I have good news for you!
There are several non-configurable files here which increase your starting inventory capacity. You have options!
A reasonable bump to 200, the default 400 of the original inventory capacity mod, a freeing 1000, and finally a ridiculous 5000.
I just choose the ridiculous 5000 from Frosty Base Inventory Capacity file.

Complete War Table Operations without waiting - for Frosty[www.nexusmods.com]

• Every operation has been edited to have no time wait, or a very (<2min) limited time wait to complete.
  
• Includes every single timed operation in the game, including those in the DLC. As such, it requires the DLC to be installed.

Faster Attack Speed[www.nexusmods.com]
This mod increases attack speed. There are three versions to choose from:

• Faster Attack Speed - Tier 1 - Slightly increases your party's attack speed.
  
• Faster Attack Speed - Tier 2 - Moderately increases your party's attack speed. (Recommended)
  
• Faster Attack Speed - Tier 3 - Greatly increases your party's attack speed.

When the game increases "attack speed", it's actually increasing the speed of all of your character's animations in combat, including the walking and running animation.

More Banter[www.nexusmods.com]
This mod guarantees that you hear banter about every 15 minutes. By default, the game has some sort of counter running in the background that activates somewhere between 10 - 20 minutes. When this happens, the game will either play banter (if available) or do nothing. By telling the game to ignore the random 'yes or no' chance of the counter, the mod forces banter to play no matter what (unless you're in a loading screen, in which case the banter should play afterward).

Improved search (Frosty)[www.nexusmods.com]

• Increases search radius. The original value is 20, i changed it to 70.
  
• Increases search duration. There are 2 versions: 10 seconds and 15 seconds. Install only one.
  
• Removes the line of sight requirement. Thanks to blood magic your Inquisitor can now see through walls!

No Search Pulse Visualization[www.nexusmods.com]
Removes glowing circular pulsing effect on the ground while searching.

All other searching effects, and the sounds as well, stay the same:

• the glowing dots on the compass showing discovered POI stay visible
  
• the warning pulsing circle on the compass when you close enough to the hidden objects stay visible
  
• the direction for hidden objects with an additional pulse on the ground stay visible as well.

Silent failed search[www.nexusmods.com]
If the search function finds nothing interesting nearby, it will no longer make that "pssh" sound, it will just stay quiet. If there IS something of interest nearby it will still make a sound, so that you know where to look.

It will still make a sound for things that light up on the map e.g loot, collectibles, or facilities for armor, weapons, potions or requisitions, etc.

Made because player spam the search button and tire easily of the sound, didn't see the point in hearing it if there was nothing there.

No Boundaries[www.nexusmods.com]
You are no longer stuck to the playable area.

• All Out of Bounds respawn triggers are now removed.
  
• All Fatal Falls (>50m fall) respawn triggers are now removed.

Fly[www.nexusmods.com]
Fly by holding the jump button.

The above two mod enable you to fly around the map making exploration faster and enjoyable. Don't fly too much though. You are supposed to walk through most areas.

The Tactician's Renewal - Unlimited[www.nexusmods.com]
This is a basic mod that allows the respec amulet, The Tactician's Renewal, to no longer get destroyed when you use it. Simply equip it to respec, then un-equip.

Infinite Crafting Materials[www.nexusmods.com]
This is a simple mod that adds infinite amounts of all of the crafting materials used for weapons, armor, potions, runes, and masterworks, infinite Amulets of Power that can be used by any party member, and infinite of one of the major trade contracts that increases Inquisition experience to the Re-Spec shops in Haven and Skyhold's Undercroft. It also increases the amount the shop buys items for to 20x their value so you can afford everything it sells, all in one convenient place.

Install with Frosty Mod Manager, and run the game through it with the mod active to use it. All DLC is required

Skip Fights[www.nexusmods.com]
This mods allows you to kill most enemies instantly and their experience points are granted as usual.

Extended Settings[www.nexusmods.com]
Extended Settings is a modular mod that expands the in-game settings. It increases the max and min sliders, while also allowing you to get more precise numbers.

• Increased Sensitivity - Zoom, Camera, Mouse and Smoothing Sensitivity.
  
• Boosted Volume. - Dialogue, Sound Effects and Music Volume (See video for a comparison).
  
• Increased Resolution. - Gamma and Graphic Resolution.

I found the feature which allows me to increase Gamma very helpful. In the original game, it is very dark and very difficult to see in places without light.

Tactical Camera Zoom[www.nexusmods.com]
Just a simple mod that expand the maximum tactical camera zoom.

ConversationCameraZoom for Frosty[www.nexusmods.com]

The Short List - Fully Stocked[www.nexusmods.com]
The Short List is an Inquisition perk that says:

• Merchants eager to win favor from the Inquisition will give access to special offers for rare inventory.
  

Normally once you unlock it certain shops will get special items added to their inventory, but only one at a time and randomly each time you load into the area. This mod adds all of the special items to their inventory once the perk is unlocked instead of just one at a time. Now you don't have to save scum in order to get the Special Item you want.

NOTE: This still requires you have The Short List perk to see them. See the wiki page linked above for a list of items and merchants.

Intuitive Controls Mod[www.nexusmods.com]
Basically the mod changes the camera so it now works as expected from common FPS/RPG games and adds convenience/efficiency features, including the attack behavior of previous Dragon Age games. The result is much more fluid gameplay that makes it feasible to play without pauses and other annoying aspects.

Below is a good SS build I like. This video includes tactics suggestion too.