I was running around in Twilight Highlands, and found this really great place to farm junk boxes. The location is in a cave at 18,15 on the map, it is the top northwest corner. Twilight npc's are running to a way gate inside the cave. If you park yourself just infront of the teleporter in the cave you will be able to pick pocket every mob that constantly runs by.
Hope you guys can find this helpful.