Relax your Face!
With all the research that's been done on how important a good night sleep is, the mind/body connection is clear. A quiet mind helps quiet the body, and a relaxed body helps quiet the mind. I recently read a study conducted by the military on research done to help soldiers go to sleep in pretty much any situation (except on duty/in battle of course), generally at around 2 minutes. I'm paraphrasing, but the process goes like this: 1) get as comfortable as you can. This includes sitting with head on desk as well as stretched out. 2) Relax, starting by relaxing your facial muscles and dropping your shoulders away from your ears. 3) Focus on breathing, not shallow, long in/long out. 4) Picture a place in your mind that is calming to you - under the palms on the beach, on a mountain top, in the deep forest next to a stream - your happy place.
It takes practice, and it works under different conditions to varying degrees. I generally can fall asleep, but when I wake in the middle of the night, I've used this technique many times to relax and quiet my monkey chatter. While I'm not always successful and falling back into a deep sleep, it does help me relax, and it all starts with relaxing the facial muscles. A simple exercise is to just try to relax your facial muscles. If you pay attention you'll notice (at least I do) that we tend to scowl/frown when we are on task. Make an effort to smile the biggest smile you can. Like the Joker in Batman. Exaggerate your facial expression in the opposite direction you typically hold it. When I get up in the morning and get that cup of coffee, I'll feel my facial muscles kind of bunched up and do The Joker. Feels Good!!
Then the next time you're falling asleep, don't do the Joker, but pay attention to the tension in your cheeks and jaw, and focus on relaxing/releasing that feeling. Then go from there and see how it works and feels. Again, take practice, like a couple of weeks to really start feeling progress. Give it a try. To Good Sleep.