- Style a box🜚make a cuboid (or other convex) space; change a texture; keep improving it until you're bored
- Block out encounters🜚make fights out of combinations of baddies and the bare minimum of grey-boxed geometry
- Study an enemy🜚choose a custom monster from a mod (or a standard one) and play around with it
- Generate something🜚use any tool that can programatically generate brushwork
- Chiaroscuro🜚make a visual primarily out of light and darkness
- Texture subset🜚take a WAD or two, and make a lean collection of textures that go together