I started staying up later and later when I had trouble either going to sleep or waking up and not able to go back to sleep. I used to get up and do many things (often what I didn't get done during the day that I had hoped to do.) I found if I just stayed up late until I was tired, I would fall asleep fairly easily and I stayed asleep, or went right back to sleep if woke during the night. That really reinforced staying up late!