I haven't made one, but I would think that it would be fairly easy to do. Go to www.earlenescakes.com
and check out the pearl molds. Also check out her instructions for bows or any other instructions that you like for making a fondant bow and you could just attach a string of these pearls to the edge of your fondant ribbon prior to forming it into a bow, or after the bow is formed. Also, the pearls are very pretty when you embed them into the ribbon itself - I usually use a bit of royal glue to do this - 1 tsp. meringue powder to 1 tsp. water. Just be careful not to get excess on the fondant ribbon. I find that the pearl or lustre dusts do not adhere well to areas where the royal glue has dripped.
Hugs Squirrelly Cakes