All of these are done by referencing the view outside my window.
Finally got myself to do something consistent with an attempt to create at least something each day, although it has been hard to keep that promise in the middle of school, as well as days getting shorter and shorter.
Nowadays the dark comes so fast I rarely have a moment to paint things while it's still light outside.
My general work process has been that I have the silhouette of the forest/land ready and mostly just focus on the sky part. It also makes it easier to capture it all since the lighting/cloud/etc situation changes so fast especially during sunset/sunrise.