When I can’t sleep, I turn around and sleep “upside down” - moving my pillows to where my feet were beforehand, and my feet to where my head was beforehand - and I stick with that for a week or so. It gives me a week or so without insomnia and then wears off, so I have to turn myself back around for the next 7-12 day period.
Admittedly this could just be a me thing, but let’s put our faith in this method and let the power of placebo effect take hold. Boom, minor bouts of sleeplessness are cured.
What are your own examples of this?
If you have a song stuck in your head, and it’s driving you a bit mad: listen to it. Something about your mind trying to fill things in (it’s been many years since I’ve read this bit of advice, and unsure entirely on why).
Or try to rememberr how the song ends.
Basically songs stick in our head when we can’t finish them, so songs with really subtle endings or heavily repeated phrases will stick the most.