Which hand?

I don't wear watches so ¯\_(ツ)_/¯

well for the wrist it's the opposite side of your preferred hand

do you wipe with your right hand?
You can't comfortably do that if you wear a watch. Just 1 example.

I change wrists once in a while because it irritates my skin

I don't usually wear watches but when I do I wear them on my dominant hand. (Right)