learn how to fall well. If you can fall well, it gives you a world of confidence. Drop, flop, roll. Don't stick arms out (good way to break a wrist), allow the roll to carry your movement so your neck/back is safe. I'm always surprised that stuff like this isn't taught along with "don't wander round behind a horse" - there seems to be too little focus on teaching what to do when things go wrong in most circles.
I used to be a competitive gymnast so actually I do know how to fall :P Never broken a bone falling off!