I work nights. That cured my insomnia. I sleep like a baby during the day.
The thing I hate is when I want to watch a show on TV and I keep nodding off in the recliner. So I hit the sack and, of course, I'm wide awake.
I know it's cliché, but read a book when you're tired. If I'm tired I usually don't last long until I'm out. Also, jerking off. Don't know how good rubbing one out works for ladies, but works OK for me.
I know you want to avoid taking anything, but you can try chamomile tea which is a very mild for relaxation combined with a boring book. Next step would be a melatonin 3mg tablet.. In is a natural substance produced by your body to induce sleep.
Next step up would be an alcoholic drink and after that an actual over the counter sleep drug like benadryl.
Or I could come lecture you until you'll fall asleep of boredom, LOL!
A good workout sometime earlier in the day. Stay off the booze. Don't eat too late. A good book of fiction to read at night instead of watching TV. Sex if available. Jerking off if necessary. No drama. Do I follow this every night? No way, but it works for me when I need a good nights sleep.
Never had insomnia, my problem was always getting a full night sleep, 3 or 4 hours max. Last week I was given anesthesia............been getting 8 hours straight every night since. Now if only I could use my morning wood when I wake up