I've always put the belt tip to the left. I got into a heated discussion with my wife one day about it. I said it should always go left and she said it can go either way. Who knows, maybe women's belts do go either way.
As for the button question, women's shirts (and pants) often will be on either side. Historically, they were reversed so that women could be dressed more easilly by servants. However with the surge of women wearing men's clothing, manufacturers have started putting the buttons on either side without any rhyme or reason. My wife complains to me about once a month about something with the buttons/zipper on the wrong side.