We're using a utility called Genetica to help create AaaaaAAaaaAAAaaAAAAaAAAAA!!!'s in-game textures:
Rather than painting brushtrokes, the program allows us to tell it how to twist, turn, and otherwise manipulate an image until we get it to where we want: "Create a circle. Create an arc. Create a checkerboard. Cut the arc and circle out of the checkerboard shape. Trace outlines. Make it glow."
For example, each node in the below image is a different process applied to a bunch of circles:
We combine all these to create concentric arcs, then apply a series of different operations:
When we render that to a texture, we get something that looks like this:
If we want something different, we can tweak some of the operations and re-render. For example, if we were to add in the hand-drawn shape of a jellyfish, and replace the arcs with circular cells (generated via a built-in algorithm), we'd get this:
When used in-game, the rings looks like this:
Check out Genetica
here -- it's a lot of fun.