I can never decide whether to lie face up or sideways. See the below list of body parts and preferred sleeping position.
Feet: face up
Right leg: on my left side
Left leg: on my right side
Hips: face down
Shoulders: face up
Right arm: on my right side
Left arm: on my left side
Neck: anywhere attached to head and body
Head: anywhere touching cool side of pillow
Hair: just chop it off and hang it up
You see, all of these can be fulfilled at the same time with the exception of neck. Go figure.
P.S.: I will pay good money if someone would make a graphic of this similar to the kind at the butcher's about parts of a pig. Um, wrong idea. Offer still stands.