Things that have helped over 40-odd years of insomnia:
Zopiclone from the doctor. Only for a week or so, until just knowing it's there if I need relaxes me enough to send me to sleep/ (This was many years ago when the insomnia was at its worst.)
Snoozeband playing an audiobook of a favourite book I've read many times. (Miss Read or Bill Bryson are favourites for me).
Change position in the bed, even turning head to toe if necessary.
Become a Bed Burrito- fold duvet in half. Take all pillows. Insert self in middle of duvet burrito. I think it probably mimics swaddling. You might have to eject any partners/dogs/cats from the room.
Get up and go downstairs. Make warm milk, sit on sofa to drink it, have biscuits. Return to bed.
Read until your eyes are drooping on their own.
Magnesium taken one hour before bed.
A hot bath.
If all else fails, resign yourself to not going to sleep and remember that you'll get through the day 'ok' on just a few hours' sleep. Sometimes this relaxes the brain enough to switch off.