I’m going through old hard drives and finding forgotten stuff. This cartoon bear in a hat gives pretty good advice. I found this and immediately did some wrist stretches and it felt pretty nice.
I got these stretches from my Mom, who got them from her physical therapist. Mom hurt her hand playing handbells but the exercises seem to work for cartooning-related cramping too.
Please be careful with your arm-parts. Do not take medical advice from a cartoon bear in a hat.