I work on hardware development, that matches pretty well the time I can spend on high-creativity design tasks. I fill the rest of the time with tasks that could be outsourced, like assembling prototypes or laying out circuit boards, but I do myself because they are more like relaxing puzzles than demanding work.

When I have to work on single a software-only project, after about two weeks of sitting at a desk for eight hours a day, I absolutely have to do something else.