This isn't exactly a hidden exploit but something I found that is very useful. On the far west end of storm peaks their is a village of the vyrulk women and death angels, the one required for the Bruhndil village dailies once you finish the chain. The regular women have a buff they cast on themselves when they go into a fight that increases crit damage by 50% and increase spell crit chance by 25%. this buff can be spell stolen and it last 2 minutes no matter when you cast it. This doesnt sound like much but I was shocked to see myself hitting 8k frostbolts and my blizzard aoe was doing 3k a shot on crits. You can use this buff repeatedly to grind the mobs in the area which have a fast spawn rate for whatever you want. The humanoids drop frost weave, relics, and the usual drops and the valkyries drop a grey dust but they are great for grinding XP or loot and they burn fast because you will most likely be 2 shotting if not 1 shotting everything their, their are also dragons in the pit which drop chilled meat. Just something I thought I would share since I have gotten some decent drops off the warrior women their and I can kill 5 in about 10 seconds.