When I’m stressed I can have really bad middle-of-night insomnia. A few months ago it was terrible. I came across an article about some guy who said to only go to bed when tired and to get up at the same time every morning no matter what. It was hellish while I did it, but after a week or so it started to work. Then after about two weeks, I set a bedtime schedule for myself while still keeping the same wake-up time. Since then, if I do wake in the middle of the night, I treat it like meditation (with the idea that meditation counts as rest) and just lay there focusing on my breathing. I haven’t had a three-hour awake time since, and usually it’s not more than 20-30 minutes.