If you’re having a hard time falling asleep: lift some weights!
I’ve done this countless times. My mind goes around and around in circles, thinking this, thinking that. Sometimes that is useful; it helps me sort out the days events, think things through. Usually there is a time when the thinking needs to end – it has just become a habit, a draining one.
Nothing shifts the mind more for me than some low-rep weightlifting, around 3 reps is best.
Even if you never exercise or would think of lifting weights for anything else, keeping some free weights around (which can usually just be stashed in a corner – one dumbbell with 30 lbs or so is the most almost anyone but very strong people need) is a great way to go.
I was rambling in my head last night and after a certain point I thought, “this is ridiculous”. So I got up, did 3 of my deadlift-curl-clean and jerk presses with the 30lb dumbbell for each side, and then went back to bed. I had been up about 3 hours beforehand – I let the ruminations run a little long – but of course I fell asleep shortly thereafter.
I hope this tip for sleeping well helps you.