Found a minor thing, which is boosting your dmg a bit.
Here is what to do.
Call Mastery Pet (Tiger)
Activate Mastery Buff
Stand still until you get your DMG Buff from Mastery
DO NOT MOVE! Put yourself in right position from where to start the boss.
Dismiss Pet
Get Crit/Haste Pet, whatever you like more.
Your mastery should stay buffed and you have XX% more dmg while standing still, but you will have 5% crit in addition.