I start most of my environments with a relatively big texture brush. I try to use various colors and the colors will usually inspire the rest of the painting. I use a black layer, set to color layer adjustment to make sure my values are correct. Everything closer is darker and further lighter, creating atmospheric perspective. For details I use a sharp almost like a pencil brush for a crisp look. The painting is meant to be really cheerful, so for shading I try to use colder colors instead of grays. I also always consider that there needs to be a focal point, so for this painting I added a fun little mysterious house.
There is a final version of this artwork.