Mastery = Haste > Crit > Versatility > Intellect
Mastery and Haste are your best stats for Single Target. Haste usually pulls a little bit ahead if you’re using Wracking Brilliance or Inevitable Demise. Mastery gains a lot of value in every Cleave/AoE scenario.
Intellect: Raw damage increase on everything.
Haste: Increases cast and tick speed.
Versatility: A weak damage multiplier and damage reduction.
The best way to calculate stat priorities for your character is to "sim" your characterFind out how to sim
Troll > Goblin > Undead > Nightborne > Orc > Blood Elf
Human > Void Elf > Gnome > Worgen > Dwarf > Dark Iron Dwarf
The enchants you use depend on your stat weights. Both Mastery and Haste enchants can be useful, but you should sim yourself before enchanting your gear.
Mastery: Accord of Mastery
Haste: Accord of Haste
Mastery: Masterful Navigation
Haste: Quick Navigation
Gems are depending on your stat weights. Both Mastery and Haste gems can be useful, but it is always best to sim yourself before socketing your gear. It is also recommended using one Intellect gem if your Intellect is simming better than both your Haste and Mastery.
Mastery: Masterful Sea Currant
Haste: Quick Sand Spinel
Intellect: Leviathan's Eye of Intellect
Health Potions: Abyssal Healing Potion