I’ve leaned to put myself to sleep by concentrating really hard on relaxing and blocking out other thoughts. I take 5 breaths focused on 'am i comfortable? - good position, pillow just right, temp ok; then i take 3 breaths focused on relaxing each body part starting with my foot- feeling it sink into the bed, working hard to not let other thoughts creep in. I’ve never made it to my head.
I have extensive practice in straining to force myself to concentrate. Much like moving one’s bowels, pushing hard doesn’t necessarily result in better output.
On a good day with a decent amount of sleep, good food (not too light and not too heavy) and interesting tasks, I find that I can dive my head pretty deep into concentration and really filter out the world around me.
Doing this takes a lot from me, so it usually only lasts up to around an hour before I need a good break.
But most days, I don’t end up concentrating that hard.