If you are skiing off-piste, never ski alone. If an accident occurs, nobody will be there to dig you to or to go for help. If you are in a big group skiing off-piste, never let more than one person at a time ski down. This goes for both the trip down the mountain and when you are traversing. This resuces the pressure on the snow and means that if an accident occurs there will be someone on hand to help dig out those that have been buried, and someone to go for help.