>>3958775get lots of batteries and keep held tight to your skin. sub zero temps will kill a battery in a quarter the time as at normal temps.
Don't rely on auto metering or white balance, the snow will fuck it up, take test shots, use a grey card.
no you don't need ND filters, but a polarising filter is a good call.
Scout good spots as early in the season as you can, drops and jumps are cool, but also pay attention to the background.
Get buddies with the best ski/board staff on the mountain, they will work with you to get good shots, they probably have more experience of good angles, and knowledge of the mountain.
be up early, sunrise, fresh runs, first tracks, again, befriend the lifties.
get organised, faffing with gear in the snow sucks dick, as does trying to adjust settings in gloves, as does adjusting settings with cold hands.
board boots are much more comfortable for trudging in snow than skis, and boards are easier to carry.