On open slopes you'll just have to hit the deck, feet uphill if possible, with head under arms. On steeper terrain you'll have to become a mountain hugger and hope the trajectory of the debris clears you. Silverstein's Mt Wilson climb . Snow slopes must be tested carefully. They may have hard spots that don't show or be soft at the edge.
Any steep slope has avalanche possibilities.
The distress signal is three short, sharp whistles or calls repeated at intervals. Do not use anything that sounds like it unless you are in need. In calculating how much time to allow, consider altitude and obstruction along with distance. People who walk 3 miles an hour on the level will normally go up hill at around 1. Minor rock problems, willow matting, bogs, windfall, ice, and other obstructions decrease speed incalculably.