I frequently evoke envy in people with my ability to nap virtually anywhere - airports, trains, arms folded across knees with head resting on arms, noisy living rooms, whatever. (I don't get sleepy at work usually, I have too much to do). My method: first, only works if sleepy, or if conscious that sleep is really necessary. Second, obviously, avoid stimulants pre-nap. Third, get in a position where your head won't f…
I think it works by quieting my internal voice and giving an image to the process of going to sleep.