At the green area called Ruby Dragonshrine in Dragonblight (Northrend) there are several friendly dragonkins named Ruby Guardians fighting Frigid Ghouls around the area.The thing is, those Ghouls have a quick 3-4 second respawn timer and rewards xp as a normal lvl 71 or 72 mob. They are easy and safe to grind if you're in the area.
All you need to do is to tag a ghoul near the guardian and damage them once or twice after. Then let the dragonkin take agro and kill it for you while at the end you will get to enjoy almost full xp.
This method is simple, safe, and rarely anyone around. More importantly, they also drop loot.
Usually the next mob spawns close to the place the last one was killed, so if in the event the Guardian is fighting too far away from you, all you have to do is kite the Ghoul over.
