I have several projects at my hand. When one is working, I usually head to the other projects and check whats going on in there.
Usually I stay vague in my project-prompts, so there's is a lot of explanation and advice from claude and its agents to read over, to consume and think about and to develop new ideas or solutions (canibalize other projects things for new iterations, appproaches and such). I keep them busy, so they feed my non-busy time.