1) Dress in layers, so that when you're more active, you can unzip to control your temperature.
2) Use clothing made from materials that still insulate despite being wet, such as wool and some synthetics.
3) Wear mittens with thin gloves underneath.
Your hands will be warmer, and you can adjust your camera controls more easily by removing the mittens.
4) Use hand warmer chemical packs.
1) Place a clear filter (UV, Skylight, or Haze) on your lens.
If the filter gets wet, you can easily dry it off with a soft cloth.
2) Carry a spare battery inside your coat.
If the battery in your camera becomes sluggish, due to the cold, switch the battery for the warm one.
Lithium batteries are more cold friendly than other battery types.
3) Use a rain cape with a wide-brimmed hat, if snow is falling, blowing around, or could drop from an overhead evergreen tree branch.
4) Recalcitrant tripod legs can be made to operate more easily with silicon spray.
5) Cover the upper portions of your tripod legs with pipe insulation, so the cold metal isn't touching your gloves or shoulder.
6) Your tripod manufacturer may offer "shoes" for use on tripod legs in snow.
1) Avoid breathing on the viewfinder and lens.
2) LCD screens may go blank.
If so, use the display in the viewfinder.
3) The heat that sensors create is one cause of noise.
Cold weather mitigates this heat, of course.
You'll have less noise when you use high ISO settings or long exposure times.
5) If you measure the light from snow in sunlight, your exposures will be too dark.
Take light readings from a medium-gray or medium-colored surface that's in the same light as the snow.
See Beecher's Handouts.
1) Place your camera in a case or plastic bag before you bring it indoors.
You'll reduce condensation from forming on and inside your camera.
Allow the camera to warm up for about two hours before removing the camera from the case or bag.
Avalanche Aware - Safe Travel in Avalanche Terrain John Moynier
Don't Die on the Mountain Dan H. Allen
Paradise Below Zero: The Classic Guide to Winter Camping Calvin Rustrum