When I'm feeling out of sorts, as I have been lately (mostly headachey, but it affects the mood too), I do this for relaxation. I stitch together a booklet and smoosh gouache paint on the pages. Whatever shapes come to mind. It's a sort of doodling with a paintbrush, I think. There's something about a brush loaded with paint gliding over paper. My sister gave me the Waterford glass paperweight decades ago. Little did she know how handy it would be for keeping paper down while the paint dries.
Be well, be safe, be happy.
Simplicity is the removal of the useless and the unnecessary--source unknown