Everyone hates crashing, but crashing has its good points too, and you CAN prep for it so you won't get (so) hurt.
Back in the olden days when I learned to ride horses, an important part of learning to ride was learning to fall. The basics were, draw the arms to the chest, round the back to get as much into a ball shape, and try to twist a little so that your ball shape can spread out and lessen impact as you roll it out--the tuck n roll. Relax so that your body can absorb the impact and be springy in the joints. Don't "brace for impact"--the idea is to spread out the energy over a wide area of the body, and then channel it out and away, instead of focusing impact on a small area and trying to absorb or stop the progress of the energy.
Here's Ryan Dungey's awesome crash with a side of tuck n roll.
See how his legs are relaxed enough so his joints boing(instead of tearing tendons or breaking ankles), and he tucks into a ball so that 1) he uses his momentum to roll like a ball into a somersault and he ends up on his feet to RUN to his bike, 2) he doesn't do a face plant(possibly injuring his neck).
On the trail where there is extra stuff to impale/crush/stab/smash you, you can add in holding on long enough to aim for a soft(er) landing spot, or giving it some throttle to aim you to a better landing spot(or hey, you just might pull it out and save it). Or at least try, ha.
Putting out your hands to break your fall is just about a guarantee for a broken wrist(probably a scaphoid, which requires extra futzing to get it to heal properly). It does take mental reprogramming to make it a new habit to bring the arms in to the chest and get ball-y and relax-y spring-y. If you can mess around with pushing your limits on a relatively safe terrain, ie crash on purpose (wearing all your gear of course!!!), you'll get three things done--overcome the mental fear of crashing to avoid the panic freeze that always makes things worse, relearn safer crashing technique, and actually find out where some limits are so you can ride faster and better.
It goes without saying that strength and flexibility training make all this EASIER with muscle response as well as enabling your body to withstand more force without tearing and breaking.
And by the way the movie Falling Down is on my top ten list!