(certified in Cognitive Behavioral Therapy for Insomnia - CBT-I - and long time teacher of mindfulness)
There are about 5 or 6 research areas that are associated with good sleep. This excellent article mentions two. Most of the suggestions relate to sleep hygiene; the wind down period and sleep scheduling are core aspects of CBT I.
The success rate of CBT I is much higher than that for most psychotropic medications (those for psychological issues) and also better than sleeping pills, melatonin and CBD (I know, some of you swear by the last 2 - I’m just citing general statistics).
OTHER AREAS
MINDFULNESS
The 50% cure rate of CBT I is raised to 70-80% by mindfulness. Why? The overwhelming first cause of insomnia is trying too hard (I know, you think it’s age, menopause, and whatever - no, it’s effort fullness, at least, according to research.
DREAM RESEARCH AND LUCID DREAM PRACTICES
Most people who devote themselves to lucid dream practice develop great insight into their dream and sleep patterns. Regarding insomnia, EVERYBODY goes through a period of hypnogogic (psychedelic type imagery) experience. Research has supported the fact that the more you can become aware of this hypnagogic phase, the easier it is to fall asleep. My get to sleep and get back to sleep time diminished from as much as an hour down to a few minutes when I learned about this many years ago.
MUSIC
There is some, not very good, evidence that music CAN be one of the most powerful aids to sleep. From the research I’ve seen (and conducted) my sense is that all the other techniques mentioned can be enhanced with the right kind of music.
YOGA NIDRA
Can’t say much here to give you the sense of how powerful this can be. There is research showing the possibility of yoga Nidra CURING PTSD! I’ve found, despite all I know about CBT I, mindfulness and music, that the combination of 1 or 2 Yoga Nidra exercises and being mindful of the hypnagogic state has made good and quick onset of sleep guaranteed. Very powerful stuff!