[jdietrich]

There are a number of excellent artists who have cerebral palsy or tetraplegia. If you have limited fine motor control, you can paint or draw in large-format using gross movements. If you shake or twitch, you can work in mosaic, collage or pixel art. If you can't grasp objects, you can use a typewriter to make pointillist drawings.

[amyjess]

To be fair, I've recently gotten into typesetting anime fansubs, and I've found it to be highly rewarding.

It doesn't require any fine motor skills, as it's all done in a really janky scripting language called ASS. I can do all kinds of four-dimensional text transforms just by writing code, and I've been able to produce some wonderful-looking effects.