Right after the kitchen project we started our Tree Houses. We were required to do interior and exterior views of our tree house, set to fit in the same "film" as our kitchens.
In between thumbnailing and refining ideas we did two practice paints. A close up on a tree, and the whole tree.
Variations based on my better thumbnails.
The final sketches under a quick color and lighting study.
And the final paints! There's some compositional, lighting and color problems but I am significantly more satisfied with my treehouses than I was with my kitchens. I think I'm starting to get the hang of digital painting.