I sewed the ribbon along the busk by hand. I figured I was going to have to baste anyway, so why not.
I just folded the top edge of the ribbon under and used a back stitch. If you look closely at the top of the right vertical ribbon you can make out the fold. I measured my stitches afterward and they came out to 14 per inch. Probably a bit smaller than needed to do the job, but I'm very happy with how they look. Tonight I'll do the ribbon along the other side then it will be on to flossing. Really.