Not a productivity post, not a self-help list. Just the actual things that work for me when a day is going badly and I need it to stop going badly. Your mileage may vary but these are mine.
Music, immediately
Not as background noise — actually putting something on intentionally and letting it be the thing I'm doing for a few minutes. Music is the thing that most reliably shifts my internal state. On bad days I tend to reach for something familiar rather than anything new. The familiarity is part of the point.
Claws
This one is not optional. If Claws is available and willing (she has opinions), being sat on by a cat is one of the most effective resets I've found. There's actual research on this — something about the physical presence and purring. I don't need the research to tell me it works, I already know it works. She's been one of the constants through genuinely difficult periods and I don't think that's a small thing.
Building something small
When a day has been bad in a life way rather than a work way, sometimes the best thing is to make something. Not a big project — something small and completable. A tiny utility, a quick script, something that goes from nothing to working in an hour. The act of making something functional is a good counterweight to days that feel like nothing is working.
Stepping away from screens entirely
This one is harder and I don't always manage it, but when I do it actually helps. Even just half an hour of doing something that doesn't involve a screen — being outside, making food, existing without something demanding my attention. The brain needs space that isn't filled with input. Bad days often involve a lot of input.
Talking to someone
Usually online, usually text, usually someone who gets it without needing a lot of context. Not necessarily to solve anything — just to have the day witnessed by another person. It sounds small but it makes a difference. Being alone with a bad day and having someone around for a bad day are different experiences even when the bad day itself is the same.
None of these fix anything structural. But they make the day survivable and sometimes that's the whole goal.