Interface
To get a rough idea of what your UI could look like, I will quickly go over what add-ons I use myself. To move my bars around I use Dominos (Bartender works pretty much the same).
For my frames I use Shadowed Unit Frames (own HP bar, target HP bar, group frame, boss frames,etc.)
For nameplates I use Plater. This add-on can feel very overwhelming, so feel free to play around with it, or simply import a profile of your choice.
Last but not least I use WeakAuras to track all sorts of buffs and debuffs. WeakAuras are also essential for both Raiding and Mythic+ content.
If you want to mimic my UI, you can find an import code for my Shadowed Unit Frames profile, as well as a link to my WeakAura pack, further down in the WeakAuras section of the guide.
Macros
Here are some useful Hunter macros everyone should have:
Trueshot, Trinket & Berserking Macro
If you have a trinket which cooldown lines up perfectly with Trueshot, you use both at the same time. This just gives an extra action bar slot for anything you want. In case the trinket is out of cd and Trueshot is not, you just press the macro to use the trinket.
#showtooltip
/cast trueshot
/use Berserking
/use 13 or 14 (Trinket slots)
Aspect of the Turtle Cancel Aura
You can cancel Aspect of the Turtle by pressing it a second time but it has a small delay in case you click it too many times in a short period of time. This macro removes that delay so use carefully.
#showtooltip
/cancelaura Aspect of the Turtle
/cast Aspect of the Turtle
Misdirection Mouseover or Focus Macro
Misdirection is an important ability in Dungeons but also in Raids: This macro will cast Misdirection on the target you are currently mousing over. Otherwise, it will cast on your Focus target.
#showtooltip Misdirection
/cast [@mouseover,help,nodead][@focus,help,nodead]Misdirection
Party Leader Misdirection Macro
This macro will cast Misdirection on the Party Leader.
#showtooltip
/cast [target=party1] Misdirection
No channeling macros
#showtooltip Aimed Shot
/cast [nochanneling:rapid fire] Aimed Shot
/cancelaura Aspect of the turtle
This has to be put in every spell that you might cast after Rapid Fire, like Aimed Shot, Multi-Shot, Arcane Shot and Steady Shot. It prevents you from clipping Rapid Fire. You can then spam these abilities even while channeling Rapid Fire without breaking Rapid Fire that has a longer channel duration than the actual GCD.
Remove the /cancelaura line, if you want to actively deactivate Aspect of the Turtle instead.
Cursor Macro for Voley and Traps
Volley:
#showtooltip Volley
/cast Salvo
/cast [@cursor] Volley
Traps:
#showtooltip
/cast [@cursor] Implosive Trap
Allows you to instantly use Implosive Trap or Volley (together with Salvo if talented) where the cursor is.
Feel free to use this Macro for all of your other traps as well.
Weakauras
Having good weakauras can really help you out a lot with keeping track of all the important stuff.
The best is just to find weakauras fitting your own interface preferences and play style.
Here you can find my personal WeakAura-Pack which I update regularly: https://wago.io/4QwOwBAhd
Here is the import code for my Shadowed Unit Frames setup:
If this doesn't suit your preferences, Wago.io has a huge collection for Hunters: https://wago.io/search/imports/wow/tww-weakaura?q=tag%3Acl3
If any questions come up, the Trueshot Lodge is your place. The discord server is by far the biggest hunter community and there are a ton of friendly people helping you out with your questions if you ask nicely.