I very recently solved my sleep problems which had been bothering me for a couple of years.

   1. I cut my caffeine intake to zero. 
   2. I forced myself to sleep at about the same time each night. (most important)
   3. I stopped using alarms. I wake up when I need to.
   4. I wear a sleeping mask which helps me get an hour more of sleep. Otherwise I'd be awake at the first lights of dawn. 

Once your circadian rhythm is retuned, points 1 and 2 stop being so important. I no longer have trouble sleeping if I drink a cup of coffee. And if I go to sleep late once or twice, it does not ruin my sleeping for the rest of the week.