Thanks so much for the input regarding the trim on the top edge of my corset. It's going. And I'll definitely add a bow. Or two. While I rework the trim I thought I'd show where the garters are placed. The placement is marked on the post Edwardian pattern, but not on the Corsets and Crinolines one.
Three garters on each side, the first is right at the center front, the second is at the side, and the third lines up with the bone casing on the last panel. Of course one could add more, or less, and you don't really need to mark them on the pattern, but once you do you don't ever have to think about it again.