It is amazing how you usually get unclipped. In every road or mtb tumble I've had I am somehow unclipped without even thinking about it.

One thing, whenever the thought or discussion of crashing comes up think to yourself "TUCK AND ROLL". Try and mentally embed that in your head and muscles. Obviously if you go down on your side it does not apply, but anytime you are going forwards or over the top, tuck your head down, roll and try not to reach with your arms. Mtb is a great teacher of this

My first hard road crash was in the low 20's; group ride and the guy in front braked and went right to avoid a hole, right into my front wheel. From mtb crashes I instinctively tucked and rolled as I went over and came out very sore with some solid rash on the back of my shoulders, elbow and knees. It hurt but I was able to ride the 10 miles back home at a decent pace.