Keep the front wheel straight. Keep off the front brake in sandy turns. Maintaining a good safe grip on the bars while keeping loose in the arms and shoulders is hard to do. Your grip can be fairly loose but ready to hold on tight as needed. Speed can be your friend.
Bikes are more stable through loose stuff at speed.
Your wheels help hold you up. Crashes, however tend to hurt more and cause more damage as speed increases and reactions to obstacles have to be quicker. Use your head. The farther ahead you can look while descending the faster you can go. Look where you want to go.