OK, I just joined this site and wanted to post a method that works for me. I work at a freight dock and do a lot of heavy lifting for almost 14 hours a day nonstop which makes this method real easy. No charts, or drugs, or bar graphs, or pie diagrams, or any hoo-haa like that. Step one: one must become physically exhausted while mentally awake and alert (energy drinks do the trick nicely here). Weight training will do. I'm not just talking a little tired but to the point that one would put considerable conscious effort in not falling asleep on the spot. You'll know you're at this point when you move your astral limb and your body limb soon follows as if attached by rubber bands. From what I understand, your astral form and physical form is supposed to occupy the same time and space. When you reach the prime time point they're slightly off from each other. Almost like a bad trace drawing laid offset over the original drawing if that makes sense to you. Step two: this is the prime moment. Get in bed somewhere quiet alone comfortable and protected. I like to use a small fan blowing softly on the bed to give the feeling of floating in water 
Anyways, from here on use any relaxation method you're most familiar with whilst staying off falling asleep. If it works you should be able to leave your body with simple ease.
Anyways, from here on use any relaxation method you're most familiar with whilst staying off falling asleep. If it works you should be able to leave your body with simple ease.