This guide is for level 15-25s and only works with spellcaster classes. This is great for leveling as you can get up to 1k xp per mob if rested
Heres a step by step guide on how to do it.
1. Stand at the start of the instance
2. Pull a mob.
3. Run right up to the left or right hand wall, this should make the mob run a long way around to try and climb up a very small ledge which you are now standing on.
4. Nuke the mob with everything
5. When the mob gets close, run to the other wall.
6. Repeat stages 4 & 5 till mob is dead.