The hardest part to me is actually falling asleep because I start to dream but have to stay focused and that keeps me awake, it usually takes hours. The rope thing never worked for me but seems to be pretty popular. If you didn't fall asleep while trying then you didn't fail but gave up.

One good tip that I never tried but makes a lot of sense, is to set your alarm for like 4am or whatever and when it goes off, turn it off and start trying.. that way your body is already prepped for it.