In many areas of the country, snow is now becoming part of the winter landscape. Even in “sunny” California, we are getting snow up in the mountains. Snow can be a wonderful addition to a scene and can create some beautiful winter photography images.
Snow can be hard to deal with for exposure because it is white. Generally, you need to give at least one stop more exposure than the meter says. Now that will vary. If you are shooting snow that is mostly in the shade, but there are some sunlit highlights, then you want to expose for the highlights and not for the snow at all. Watch your histogram - you want to be sure that there is not a big gap on the right side, but also, no clipping of whites on that side either.
It is very easy to underexpose snow badly which will crush the dark tones all together and make it very difficult to bring out a good tonal range in the image. However, it is also easy to overexpose small areas of snow in a larger scene of dark tones so that you lose detail and texture in that snow. Watch your highlight warnings and be careful of clipping of the whites on the right side of the histogram (clipping looks like a cliff at that side rather than a mountain slope that comes back to the bottom line of the histogram just before reaching the right side).
You will probably find your snow looks best shot with any of the daylight white balances. This is tricky because no matter what you do, you can get blue snow and that can be absolutely correct. If the sun is out, then shadows will be reflecting the usually very blue sky of winter. If you overcorrect for that blue, then the highlight areas can look too yellow or too amber. I find that a cloudy setting works well, sun or clouds, with snow, but this is going to depend, to a degree, on the camera model. With a scene mostly in shade, you may do okay with shade white balance, but you may find that that does not completely remove the blue, especially if you are shooting at altitude. You may have to go to your Kelvin settings (if the camera has them) and set something upwards of 9000K. You might also find it helpful to do a custom white balance (which can be done on clean snow as it is a good neutral tone).
And finally, sometimes snow just looks right with blue in it. This is especially true at dawn and dusk.
Note: Rob Sheppard is editor at large for Outdoor Photographer magazine, and he teaches a number of excellent online photography classes at BetterPhoto.com, including Creating Storytelling Photos and Successful Publication Photography. BetterPhoto's photography school also includes many online courses on natural light photography and photography exposure.