My top tips:

• Get off the computer at least an hour before bedtime.
  
• Turn your alarm clock off *before* you go to bed, not so that it doesn't go off but so that you know it isn't going to.
  
• Don't drink alcohol or anything caffeinated; not in the evening certainly, and not in the day either if you really want to sort it out.
  
• Schedule a day in which you are not committed to doing anything whatsoever, so that you have no subconscious reason to have to get up and be ready to go out. 'Noting whatsoever' also includes putting all your world-improving projects on hold and not allowing yourself to hack, full stop; this is a day in which you actually stop.
  
• Get exercise. Go for a run before bed every single day if necessary. This really does improve your sleep.
  
• If all else fails, assassinate the heads of the rogue state: take pills until your body gives in.
  

Trouble is, I do most of that already. Even including the doing-nothing days; I've been doing a lot of those for the past few months.

Exercise is a thought, admittedly; I could try that. Pills I do try occasionally, but the trouble is that in order to try it I need to know in advance that I'm going to have a difficult night sleeping (unless I want to take pills every night, which sounds like a thoroughly bad idea unless there's really no other option).

How about 'take pills whenever you get thoroughly sick of sleep loss'?