To fall..... LOOSEY GOOSEY. If you stiffen or tense up your body, you're almost certain to get hurt.
Or you could try and pull a cool one... like some kind of gymnast flip... but of course this doesn't always have the best results. In my case, it once did.
I remember once when I was on my mare, teaching her to do flying changes, she would always buck when she swapped the back. So I was in a circle, trying to get her to pop her back change... the second I stepped out, of course, she bucked. Since she had been doing them so well lately, I wasn't expecting a buck, so I was caught off guard. My entire body was launched out of the saddle, I put my right hand on her withers, my left hand smack between her ears, my legs flipped over me, and I did a cartwheel, and, ironically landed on my feet, standing centered in front of her, and managed to stop her in a split second.
The. Best. Fall. Ever. ^^^^^