I follow the "first sleep" and "second sleep" idea that
@DLgal discusses up there at post #2. It works well, as long as you don't have to be anywhere early in the morning.
When I reached middle age, I started aways waking up around 3 a.m. -- would toss and turn and just finally wake up exhausted. Now my routine is to get out of bed when I wake up at three, have a cup of coffee and a light snack and just do my thing -- watch TV, pay bills, do online stuff -- whatever I want. At around quarter to five, I put in ear plugs, put on an eye mask, and I fall asleep really quickly and stay that way until I wake up, naturally refreshed --usually at about 8:30.
Weird, huh? But it works for me. Oddly, the coffee seems to relax my body -- perhaps by increasing circulation to relax my legs. The very light snack (usually peanut butter) seems to stabilize my blood sugar in a good way.
Insomnia is a real pain. I hope you find something that works for you, OP.