Hiya! I have been playing since 2011 and just came back into the game. Lots of players ask about how to gear tanks in PvP and while gear obviously matters there is a tactic that will affect your toughness more than any stat, TAUNTS!!
Tanking in PvP is incredibly difficult due to many factors including subtle but profound differences in mechanics that tanks also rely on in PVE, namely taunts and guard. Guard will provide 5% mitigation to the ally it is applied to, and when the guard target is within 15m of the tank, 50% of the damage the guard target takes will be directed to the tank. The damage transfer mechanism only applies to PVP.
Taunts will mitigate damage an enemy deals to all allies except the tank who casts taunt. The mitigation from taunt will of course reduce the damage that the tank takes from guard's damage transfer. There are 3 outcomes after using a single target taunt:
Fail Taunt: Applying taunt to an enemy who is attacking you. This wastes the cooldown entirely
Weak Taunt: Applying taunt to a healer or any DPS NOT attacking your guard target. While you still provide mitigation, you have failed to stack the taunt's mitigation with guard mechanics gimping that taunt's effectiveness
Strong Taunt: Applying taunt to an enemy who is attacking your guard target. This is the ideal and goal of all good tanks. Stacking the guard and taunt is the goal of PvP tanking.
Using Focus Target to help track the health of a healer allows you only monitor 6 health bars in ops frames. Making the "Target of Target" visible in your UI is crucial to ensure you are applying Strong Taunts. Taking a half second to check ToT right before taunt comes up will allow you to keep taunt constantly on CD.
Don't wait to use taunt at just the right time. Use it on CD and check ToT. Keep within 15m of guard target at all times and you are on your way to becoming a legend!