A common suggestion for mountain bike riders is to go practice falling over on grass or some other soft surface so that you learn how to fall. I've fallen over enough on harder surfaces than grass to learn those lessons but it's more painful than the other method.

Crashing is inevitable...I know there are some here who say they have never crashed but they are anomalies...it's better to know something about how to crash then have it be a complete surprise. You are less likely to be hurt that way.

To be clear, I don't usually go out to intentionally crash. But I learned many crashes ago that just relaxing, going "rag doll" and letting the crash happen is far better than trying to resist the crash. I just realize that it happens and am prepared for it. That way I end up with scrapes, nice oozy scabs to pick and bruises but not with broken bones.