try:
-proper fitting boots done up tight (just loose enough to not cut off circulation)
-booster straps (live up to the hype)
-no backseat riding, keep your shin pressed into the tounge, this will also help you carve better
some boots models to try: Full Tilts, SPK, Dalbello Krypton, but you gotta try them on before buying, everyones feet are different