Spec Specific Azerite Traits
Double Dose: Currently the best single target trait in the game that you want to be stacking. It makes your mutilate apply a poison DoT on your target and with triple Double Dose just the trait itself does about 10% of your damage.
Nothing Personal: You want one of these on your gear at least. Although, using 3 can be worthwhile on a purely single target fight like Mekkatorque, but ultimately depends on the type of gear you have access to.
Shrouded Suffocation: Is incredibly useful if you're running an Exsanguinate build, in which case you'd want to have 3 of them on your gear. Alternatively, for a more all around setup, you can run 1 with Toxic Blade as it'll help make your single target more fluid & naturally make your cleave a lot stronger.
Echoing Blades: Is extremely useful for M+ and should be stacked if you plan on doing that sort of content regularly, bosses like Opulence are also an encounter where triple Echoing Blades can work, but Battle of Dazar'alor doesn't really have many AoE fights like that.
Overwhelming Power: From the third DPS ring, this is the trait you want to be stacking. In its nature, it's a bit of an RNG trait plus it has the downside of being less effective when you take damage.
Loyal to the End is a fairly decent (new) trait that gives mastery, increasing with the more people that have it in your raid. I tend to prefer this trait over something else if they are of similar value, solely because if a person dies its value raises quite a bit.
Azerite traits rotation changes
Double Dose doesn't necessarily change your ST too much, but you should be aware of your Toxic Blade buffing it, thus wanting to squeeze out every last Mutilate in your window. The problem with the trait lies in AoE; if you substitute Fan of Knives for Mutilate, it loses all its value. Therefore, if you're going to be using Fan of Knives regularly, such as for M+, you should opt not to use Double Dose and instead look at Echoing Blades.
Recommended Azerite Traits
New Essences in Patch 8.3
Breath Of The Dying is a new essence that will be gated behind Uldum Accord reputation. This looks like our go-to minor essence, with an extra bonus during execute range.
Spark of Inspiration increases the damage of people in your party, within 15 yards, by 45% on a 1 minute cooldown (when used on a major slot) and is more of a supportive essence. The minor effect gives you and up to 2 of your allies (on rank 3) a proc of haste and cooldown reduction on your main essence.
Formless Void allows you to copy the essence of your target, with passive corruption reduction. Its minor boosts your main stat every time an ally uses an essence.
Condensed Life-Force should be your go-to major essence unless you are killing the boss in less or around 3 minutes, in which case you should be using BotE. In terms of usage, you don’t need to think too much of it, but you should use it a few globals earlier on your opener as opposed to BotE that comes after the Vendetta; your CLF should be used right after putting your bleeds up.
BotE is great for both ST and cleave and especially in shorter fights. I tend to use this Essence quite often on fights where I’m not certain if my CLF will get 2 full uses, and always on Zaqul/Azshara.
Memory of Lucid Dream is your best minor that you almost always want to be using regardless of boss.
Essence of the Focusing Iris gives you stacking haste which is good overall.
Vision of Perfection only for Zaqul if you’re going down to kill Delirium add.
Conflict and Strife is great for cleave situations.
Corruption on gear has a chance to proc a positive effect, with 3 tiers of potency. The higher the tier, the more corruption on the item.
There are several positive effects on gear, some prominent ones right now are: Infinite Star, Echoing Void and Twilight Devastation.
Infinite Stars is a random proc from any ability that strikes a random target, debuffing it with a stack of Infinite Stars. This will increase damage taken by 25% from your Infinite Stars proc, stacking up to 10 times.
Echoing Void stacks up each time you deal damage, with a chance to collapse each time you gain a stack, dealing shadow damage to all nearby enemies.
Twilight Devastation is a beam in a cone facing in-front of you and is mostly good for AoE.