With a minimum of materials and only a few simple steps, you can fashion an attractive barrette from a metal hair clip.
Martha Stewart Living Television
Using ribbon that has some body to it, such as grosgrain, cut a piece that is twice the length plus 2 inches of the hair clip. Make sure the ribbon is wider than the width of the clip. Apply seam sealant to the ends. Glue the ends of the ribbon to the center with the fabric glue, creating a bow. Cut another small piece of ribbon to wrap around the center, resulting in a "bow." Apply a small amount of fabric glue to both ends, wrap it around the center, and attach the ends together.
Apply fabric glue to the metal hair clip, carefully center the ribbon on top, and press firmly. Allow it to dry for at least 30 minutes.
You can embellish the barrette by criss-crossing pieces of fabric at the center instead of using a single piece, or glue a bead onto the center piece. If you make a number of barrettes, create a holder by using a long piece of ribbon, gluing it around a simple key ring, and clipping the barrettes onto the ring.