John says:

Leon, tree armatures for a winter scene, which don’t have leaves on them, can be obtained from most manufacturers.But be sure that, big or small, the tree fits the scale you work in. As far as snow goes, Woodland Scenics makes fake snow that goes on like ballast and is easy to handle. Beware of snow sheets though. They look great around a Christmas Tree, but the wheels of the locomotive act like a magnet and can easily wrap the snowsheet around the axles. Then the real “fun” begins.
There are two ways to model a winter scene. One is to observe the scene outside, even take pictures of it, then model that scene on your layout. But it is tough to duplicate nature, and it’s easy to get discouraged. The other method is to build a creative scene on your layout without a prototype, let it set for a few days, then come back and make changes as needed.