A really important thing that I do is always have a side project / passion project on the go. Even better if that side project has potential to become passive income or otherwise boost your primary career. Then when the lean times hit you can instantly shift focus to being productive on that project and you don’t feel like you’re wasting time at all. In fact I’ve found that I often feel great during those leans times because I’m making progress on something more personal, and then feel a bit of a pinch when my workload get’s back up to 100% and there’s less time to devote to the side project again.

There’s ALWAYS something useful you can be doing during those time.