Another tip for falling asleep (again doesn't work for staying asleep, I literally slept 10 minutes last night using this to fall asleep but still woke up) is the 4-7-8 breathing technique:

Put your tongue against the inside of your top teeth and breathe in through your nose and count to 4 in your head. Hold it and count to 7. Open your mouth and breathe out counting to 8. Repeat at least 3 times.