I decided that painting on different supports is a good idea, because as convenient as my paper sketchbook it, the paint kind of soaks in and I lose any texture that I might be working on.
So I found a few junky canvases and also some other kinds of board/paper to experiment with.
These two paintings were both done with a limited color palette (3 colors plus white and a little black) which is good both for color mixing practice and also getting a unified look. It always surprises me at the end of a session to look down and see how many colors i have mixed, intentionally and by accident, using just 3 colors. I've seen some masters paint with only TWO colors and it doesn't feel lacking. There's an incredible array of color and tone hidden in just a few paints!
Unfortunately these photos aren't great, but they'll have to do for now.