Finding a subject in your scribbles.
Pay no mind to the scribbling; it doesn't have to look like anything. When you've had enough, step back and look at it. What do you see? It's good practice, and a good letting go exercise. It's also a lot of fun.
Once I'd finished scribbling and applying some paint, I turned the paper sideways, and I saw a boat in a busy port.
Simplicity is the removal of the useless and the unnecessary--source unknown