When I think to throw items, I usually toss whatever I have in my bag. That could be backup weapons, my knife collection, a trophy collection of assorted body parts, or even my lunch. I used to use individual coins as ammunition, but since they just "pass right through" I now just toss the whole sack. Sometimes if I think ahead by any degree I'll bring bolts or arrows or something, and I have reactions that let me knap bone arrows and such, which are fairly lightweight compared to stacks of metal ammo from archers.
I've even resorted to undressing and tossing clothing at them. Which is also crippling if they hit...
*The spinning nudity strikes the bandit in the eyes, tearing the retina and severing a sensory nerve!*
*The spinning rope reed fiber trousers strikes the bandit in the left lower leg, bruising the muscle and shattering the bone!*