Do something boring like studying for academic or completing some pending work, always work for me. Tho i'll advice you to adjust your body clock as sometimes your body wants to sleep but you keep yourself engage in various task and your brain don't let you sleep as its processing things that you did before .30 min before heading to bed,just put away your phone and lappy and take a nice bath drink some milk or have a light snack and lie-down in your comfortable position,it may take 2-3 days for your body to fully accustomed to that but it'll help in long run.
Regular methods don't work, sleeping drugs just make me more tired but still can't sleep, so in this situation i just accept fate and prepare to drink as many energetics as i need before my appointments.
Jog off outside. Get some sweat out then perhaps read some book. A real book not some digital on your screen.
I turn off all my devices and start.. day dreaming? Well it sometimes takes ages to sleep, so my mind starts to wander.. eventually though I sleep...
Maybe you've developed the habit of drinking milk before you go to sleep. (psychology conditioning) I mean that's what parents do to their children: "Hey Jimmy, drink your milk before going to bed!" There's also some studies that suggests calcium aids with sleeping, although I find a hammer to the head a much much more effective method.