I took Judo years ago which taught me how to fall, then
with dressage lessons tossed in where one learns to ride balance, to depend on
balance and not a horn. I have taken three falls in the last 20 years
and each one was because I was not balanced in the saddle. I have ridden
some pretty bad spooks.
So my suggestion is to take dressage lessons and if
possible some martial art. Just make sure the dressage instructor puts
you on a horse on a lunge line and has you ride without reins or
stirrups.