What jambo said!
Honestly though, prior to being married and a dad..
Routine, exercise and relaxation. Oh aye, lay off the fizzy juice/coffee etc in the evening..
I was pretty bad for sleeping when I was younger, going to sleep really late, sometimes not going to sleep at all before work. Then knackered all day, sleep all day if not at work, then repeat.
Had to force myself not to go to bed when I got home from work so that I wouldn’t be up at 2am.
Was drinking a lot of fizzy juice, too much stuff going through my head, not enough exercise for the old endorphins to relax me..
You
Get the idea.