If I do wear one it's on the left arm and face down, opposite of Bricktop's.
I prefer face down too, but its a bit tough to read when I need it in EMS situations plus it alerts the patient that you might be timing respiration, heart rate etc... and can give you a false reading.
Of course if not for ems, I'd be running the phone only like I used to.
Can still recall watches so loud in ticking I was sure the deer could hear them.