Save AoE hate for dangerous situations, ie, three or more mobs already attacking you. In those situations, one stray mob and you're going to be toast.

You don't have FFXIV Gil to hate every mob! This is the first mistake of many tanks. Just aggroing a mob by running into its aggro radius builds a substantial amount of hate.

If you do this at about 2 seconds before the mob your group is currently fighting dies, you can get the first couple hits in on the new mob, building even more aggro for yourself.

In a catacomb melee party, you can stand in the middle of the room and use hate to pull the mobs to you, reducing the running time and increasing kill speed.

Attempt to always have at least one mob attacking you constantly. Any time moving, waiting, switching targets or otherwise not attacking a mob is lost experience time.

Use the passing of aggro as an advantage: when a mob nears death, pull or otherwise aggro another mob and return to finishing off your current target. This can usually be done with a quick hate, or stepping to the side and getting another mob.

A good tank can maximize your party’s XP more efficiently than any other party class in the game.