To make sure I have time for a few non movable things each week or day. The 2-3 core things that are for me, my sanity, and my mental health. Skipping sleep isn’t great but these things would take priority on a weird day. If I found myself skipping sleep long term, I’d re-evaluate my schedule
For me these are the gym 3-4 times a week. I get punchy and anxious if I don’t go.
Daily it’s meditation and 30 mins of fiction (sci-fi and fantasy) before bed.