What's a good method for astral projection?

I have had a few out of body experiences in my past, but only one of them was self-initiated. I know that if you meditate and let your body fall asleep with your mind still awake, you can do it, but I haven't had much success recently in my attempts. As soon as I feel my body "vibrate" I lose focus. Do any of you project? If so, what suggestions can you offer me?