Depending on the fight Paladin can also pop Divine Veil -> Clemency the Main Tank
-Tops off the MT's hp, Clemency returns 50% of the heal to the PLD, which procs the Veil giving the Main Tank a shield.

Move inside the bosses hitbox and use Passage of Arms facing the Main Tank
-Can pop Passage of Arms and immediately start attacking the boss, Passage puts a 5-6 second buff on the Main Tank even if you moved around
-Great for Shared Tank Busters as well (20-30% Block on the PLD, 15% Mitigation for the Main Tank.)