A 1 hour, 1 layer warmup painting done based off a reference image. :>

I like to do these sorts of warmups before drawing to, primarily, loosen my joints and prevent the ache of drawing for long hours. It's also excellent practice for learning backgrounds, and for also how to build backgrounds and place characters in the scene in a believable way. And by doing it all fast and on one layer, I'm forcing myself to work with whatever I put down, or I have to paint over it with a new color, just like one would traditionally. It's a fun exercise!