I usually fall asleep within minutes of my head hitting the pillow. My method is to concentrate on the "lights" I still "see" when my eyes are closed. The lights tend to move about and change shapes. I try to make sense of them, telling myself, there's a mountain; there's a man's face; there's a boat on a river; there's an exploding star; depending on how the lights play inside my closed eyes. For some reason, this seems to put me to sleep almost instantly -- maybe because it distracts me from thought-provoking questions like, "Why doesn't Tarzan have a beard?"