I'm a lefty, but I do not wear my watch on either of my wrists. No thank you, I don't want to be shackled by time. I carry it on a belt-loop of my pants (on the right). I guess that makes me a hipster too?
The worst drawback of this 'orientation' was dragging your hand through the wet ink from a fountain pen all the time when I was a kid in school. The thinking was that using a fountain pen improves one's handwriting skills. Yeah, left! It's never been any good. I hate those pens.