As a leftie myself my uncle-a watch repairer- told me to wear any decent wristwatch on the left hand, because they are adjusted to spend most of their time with the winder pointing downwards.
Indeed. My Grandad who served his apprenticeship in watch and clock building in a posh jewellers shop many years ago always said the same thing and would often tell people off if he seen someone with a watch on the right arm.
He had so many clocks in the house that being there on the hour used to be deafening when they all started to chime.