I am currently leveling a shaman, as the hunter got.. well.. boring to play.
But.. Dear tanks using the LFG tool:
Stop skipping packs of mobs!
Seriously. We're here to farm XP, so that we can level up, not Justice Points. While we do get a nice amount of XP when finishing the dungeon, that is minor to what is inside the dungeon itself.
For instance, Auchenai Crypts, who are at the same level as my shaman, provides 927 to 975 xp per trashmob. (Or ((975+925)/2) = 951 overall xp per mob.)
This is with 20% bonus XP-gain from heirlooms and 10% from guild, wich most of the tanks I've encountered so far seem to have.
I get 10750 xp for completing the instance from the LFG tool.
So.. Give or take, I'd say that Auchenai Crypts got atleast 100 trashmobs we can kill. (I'll extract an log later to give a more correct number.)
Operating with that number, I get 95100 xp inside Auchenai Crypts on average.
Now, why would you skip as much as possible of this xp-pool, just to finish the instance faster?
I don't get that..