The composition of these photos is quite good. The real issue here is metering for snow. If you know how to use exposure compensation on your camera, good...if not, now's a good time to learn. Your camera meter will try and render everything as a medium gray. Usually, that's fine since there's a range of tones in an image, but in snow, the meter gets fooled. If you dial in +1 1/2 stops of exposure compensation (or +1, etc), you'll get a much brighter photo that will render the snow as it is: white. You have to be careful when doing this though, so you don't blow out the highlights.
You have a natural eye for composition, and that's the most important thing. I especially like 2, 11, and 12. The underexposure on these could be cleaned up in post processing pretty easily, which would really make them pop!