Working further on our class demo at the Michigan Art Center, I began building depth in the distant treeline and the distant ground.
Darker greens and a deep blue were added to the edge below the distant treeline. Olive greens and ochres of similar value to the treeline, were layered into the body of the trees.
The tops branches/leaves of the trees are slightly lighter than that portion just below the top. hat condition is influenced by the sunlight behind the trees, which cause the foliage in that area to become a bit muted.
I added "sky" holes to the main tree as well as "background holes" to the center body, where you can begin to see the background treeline show through the gaps in the main tree.