I agree that learning how to fall properly is key, but I still wear wrist guards for those "just in case moments". I'd really recommend buying legitimate snowboarding wrist guards. They usually have some give to ,them(both Burton and Level gloves have very good wrist guards built in to them), as opposed to the hard plastic snowboarding wrist guards, which could probably cause some weird arm breaks if you fell hard on them. I didn't wear wrist guards for my first 5 or so years of snowboarding, then one year I caught my edge going off of a kicker and had to choose between my neck and my wrists. Well my natural instincts kicked in and and I chose to put my hands down, sprained one wrist, and broke the other in a very strange way requiring a surgery and a screw to be put in. 5 years of falling on my ass the correct way(fists clenched, hands up and in front of me), and I STILL managed to break my wrist snowboarding
. I decided that I was going to use wrist guards just in case, and haven't looked back since.