Just discovered a spot on floor 5 where you can fall to the sixth into a room full of skeletons with a flight of stairs as the only exit. If you take the stairs up, then come back down and don't move, archers will shoot at you but not be able to hit you while their frost arrows pile up at your feet, allowing you to take them for yourself.
Uploaded a video of it here:
http://youtu.be/dJcK5I8XCsk