Quoted from "Biromir" Do goblinball all the time and buy exp tokens with the rewards. Not only you'll get exp, but you won't be a goblinball noob at level 60. That thing is extremely rewarding all the time. I'm gonna be looking into that.
Same for me. I just returned to my lvl 36 character. I get around 500 exp for lvl 37 quests, and need 140k exp to level. So i basically have to do ~300 quests. How am i supposed to keep up with the level of the Zones then?