For me, having nothing to do is a luxury. When I find myself in this mode, I take long walks, let my mind drift and think about whatever it feels like (usually it chooses to think about one of my ongoing projects, big unsolvable world-scale problems, future, lack of moral progress, or sex), read long-form stuff (mostly Kindle books on my phone) and generally relax and recharge, assuming that I can find a relatively quiet environment.
Previous Open Thread
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one.
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.