Spec Specific Azerite Traits
I will only be listing the azerite traits that are of impact to the spec. Any traits not listed should be avoided, bare in mind these are SPEC SPECIFIC only, not raid or open world traits.
Igneous potential: This is by far the best trait right now. Stacking this trait will increase your damage by a huge amount, at 2+ traits you will start taking different talents to empower the trait even more. Try and obtain 3 of these at all costs.
For M+ this trait will depend on the affixes. When there are affixes where huge AoE can be done, you would want to trade these out and take other traits listed below.
Lava shock: Because of Igneous being so good, flame shock becomes more valuable. This means multidotting things that don't take damage is now powerful, think Orgozoa adds / Queens Court. Because of this and Master of the elements talents, lava shock is very strong on multitarget fights.
Natural harmony: Free stats, this trait also becomes a bit more valuable when you get Igneous potential as it unlocks Icefury to be used. Icefury is our only real source of frost damage and will allow you to proc the mastery effect of this trait. Even without Icefury, the stat gain makes it very solid. This trait is extremely strong in M+ as secondary stats scale great on AoE.
Tectonic Thunder: AoE only, first 2 traits are okay for value. Adding the 3rd trait will make you want to earthquake on single target, thus obtaining the 3rd tectonic trait will increase the overall value of the trait by a fair amount.
Ancestral Resonance: Very fight dependent, however on the correct fight this can be of big value. Adding 10 seconds more of Bloodlust is very useful in the right situation.
Example: Ashvane's shield opening burst window or Azshara's last phase DPS check.
Azerite rotation changes
Igneous potential: at 2+ of this trait you will start to run different talents, which will change around your talent build:
You will start running Echo of the Elements over Earthen Rage, Master of the Elements over Storm Elemental and Icefury over Primal Elementalist in certain situations.
What traits to go for:
3x Igneous Potential = required for raiding on all fights
For single target: Natural Harmony
For cleave: lava shock is extremely powerful
Situational: Ancestral Resonance
Condensed life Force: Overall it adds nice burst and can be lined up with fire elemental. Just make sure fire elemental doesn't lose a use for delaying. Condensed Life Force is most powerful at rank 3, getting the 10% haste. Until you get rank 3 of Condensed Life force you can use many other rank 3 essences instead.
There are also other major essences that could be better for certain situations, but Condensed Life Force and Crucible rank 3 are enough for almost every single target fight.
Elemental has A LOT of minors that can all be used for different situations.
Crucible: Overall does alright damage in every situation.
Essence of the focusing iris: Big haste gain, very good for fights with cleave.
Conflict and strife: Big versatility gain, good for cleave fights and single target.
Default Raiding picks
Major: Condensed life force
Minor 1: Conflict and Strife
Default Mythic + picks
Minor 1: Conflict and strife