The Uphill Edge
Keep in mind that while you are snowboarding, always put pressure on the uphill edge of the board. So, if you are going down the mountain "toeside", that is, facing uphill, your pressure will be on your toes. This way of facing the mountain is called “toeside” for obvious reasons. If you are going down the mountain facing downhill, your pressure will be on your heels. This is called “heelside".

"Catching an Edge"
DON’T put pressure on the downhill edge. It will cause you to tip over, otherwise known as catching an edge. This is a really easy way to get hurt.

If you are heelside (that is, traveling downhill and facing downhill) and you dig the downhill edge (the toe edge) into the snow, the board will stop and you will keep going, causing you to be thrown face first into the snow. Don't put your arms out to catch yourself, try to relax and ball up. Similarly, if you are riding toeside and your heel edge digs in, Your board will stop and you won’t, causing your back and head to slam into the ground. This can even cause whiplash. Remember, watch the downhill edge whether it is toe or heel. If the downhill edge touches the snow before you make your turn, the downhill edge will catch on the snow and throw you to the ground. On the east coast this can be particularly dangerous because of the ice that is commonplace.