This is a great exp tactic, that has served well in other games. It allows you to DPS/Tank a mob, and take down elite mobs, solo... well with a little help anyways.
1. Find the Kishar Observation post in Heiron
2. Find Brosia, an NPC in the post
3. Right outside the post is level 38 elite mobs
4. Pull the elite mobs right next to Brosia, one at a time.
5. DPS as much damage as you can while Brosia tanks the mob.
6. You get an epic share of the exp (around 150k exp). If you do enough damage you get loot as well.
7. Rinse and repeat.