This instructional video re-enforces everything I've learned about riding switchbacks. I think it is exactly what the OP is looking for! Enter the turn too wide, & you risk having your front tire sliding out in the soft stuff all the other rookies have made worse. Don't cut back to the inside, & you'll get stuck in the groove that the downhill brake lockers have created.
Also as BWPA mentioned, using the biggest gear you can handle is a great way to maintain traction & constant power to the drive wheel. This works not only on switchbacks, but on any steep, loose section.
Another thing I've found helpful for downhill switchbacks is to rotate my inside knee into the direction of the turn while maintaining an upright torso.
Thanks, this is a good thread.