Nature was not drawn. So as we convey the landscape in pastel, we try not to "line out" the elements of the landscape.
Here is the snow scene in-progress. As I spread snow across the fixed drawing, the trees started to vanish. To resurrect the trees, I took a dark brown/grey flat stick (Terry Ludwig brand) and motioned left to right to bring back the tree. As we know, trees grow in rings as the round out and build wider girths. So the pastel is applied to convey that sense.
As for the snow, I chose my palette and applied the pastel. As snow is smooth, I decided to use a cloth to spread the pastel and smooth it out across the canvas.
The snow has peaks and valleys which catch (and hide) the early morning sun. So I used the same pushing approach to convey peaks in the snowy terrain.
So don't hesitate to use implements such as a tortillion or cloth, and keep in mind how your stroke with the pastel to capture growth patterns in the landscape.