I have suffered from Insomnia, on and off, for years, and I have learned a few things.
One drink in the evening is very nice but it just disturbs sleep in the long run. I am no angel where it comes to having a drink, but people who have a Dry January report that they sleep much better, after a few days.
I have also found out that if I go to bed too early, then although I go to sleep pretty quickly, I am awake again after midnight !
Last night was I stayed up too watch The Moorside, and didn't get into bed until about 23:00, but slept right through until 07:00 this morning.