Snowy Trail Watercolor

Start with these reference images:

Starting at the top with a graded wash, continue down the page with the sky color into foliage shapes and colors. Continue the same wash into snow and indicate the path.
Let dry. When the first wash is almost dry, go back into the foliage area and apply another layer of paint. This will cause some interesting shapes called rumbacks. Change the color also to make it interesting.

When this is dry, indicate trees, varying the color, size and shape. Once you have the trees in place, show shadow shapes from the base of the trees, with a blue and burnt sienna color. The shadows will follow the contour of the ground.
When this wash is dry, start to shade the trees, keeping in mind where your light source is coming from. Add branches onto the trees and some dead foliage in the snow.

The last step is analyzing the values. The value is darker on the path than the snow.