In most avalanche situations, any defensive action is very difficult. Movement relative to the debris is often impossible.
However, some of the following may be useful:
If you witness an avalanche burial:
This series of videos from Glenmore Lodge examines techniques for searching with avalanche transceiver and probes and for digging for different burial depths.
Part 1 Using an avalanche probe
Part 2 Avalanche search - shallow digging
Part 3 Avalanche search - deeper digging