While you are on the quest Soothing Spirits in Duskwood, you are given an item that will instantly kill the spirit, giving you both experience and loot. Gave 165 XP at level 25. You could either grind these things for XP (its probably faster to just quest) or might be beneficial of you want to 'farm' random world drops, or cloth or whatever.
Didn't see it posted but nothing crazy