For you specifically, I'd also consider the following:
- breadmaking (artisanal loaves)
- knitting, crocheting, cross-stiching
- figurine painting
- juggling
- slacklining
Here's my list of good "autopilot" activities:
- walking, cycling, driving
- basic cleaning and house chores
- light exercise
- basic landscaping
- doodling
- showering
- waiting in a queue/waiting-room