- Partial tip: There's often the suggestion of concentrating on breathing, usually with some kind of regular pattern. This is an alternative to try.
You'll need to have been in bed for a while, mind racing. Take how extreme that racing is and then taking a similarly extreme, almost uncomfortably deep breath to match it. This requires having been in bed for a while.
Hold it for a bit. Don't count seconds - avoid numbers. As soon as you get the vaguest hint from your body that you need to let it out and breathe normally again, do so. Try to relax as much of yourself as possible as you do that. This is not a "hold your breath till you pass out" thing. You want to go back to breathing normally.
If the breath was too deep and that freaked you out a bit, try going a bit more shallow on the next one.
This has sometimes worked for me, especially if I've been asleep already and can't get back to sleep.
Sometimes I've tried a regular breathing exercise after that.
Other times I have got out of bed and done something mindless for a while until I felt tired again. No doomscrolling.
- More traditional tip: No caffeinated beverages for at least 6 hours before you go to bed. Yes, six. Nine's even better.