oh, i interpreted the title as "what are your sleeping preferences" not literally "how" lol. But in that case: i always start lying down on my left side; when that side gets tired, i turn over to my right side to fall asleep; if i wake up in the middle of the night, i turn back to my left side (mainly to look at clock).
When sleeping on my left side: bottom (left) hand goes between my mid-thighs; top (right) hand goes around my Sqüsh beanie pillow
When sleeping on my right side: bottom (right) hand reaches under the pillow searchin for dat cool spot; top (left) hand goes around beanie pillow
Even further off topic: last year i had an insomniac roommate who slept more than i did... He has beyond severe DSPD (a type of melatonin deficiency) and didnt have medicine for it... His average bedtime was 5am (2am on a good night, 6:30am on the worst night), and woke up anywhere between 2-7pm... and on weekends he could sleep 16-20 hours/day. So the light in our room was only on a few hours a day for our rare intersecting awake hours.