I tried a few different ways to strap the wire to the barrette, and found this one to work best. First, cut a length of 3" wire.
Lay the barrette face down. Fold the wire in half, then slip it over the thong of the barrette.
Flip the barrette over.
Wrap each end of the wire around the end of the barrette so that they are on the front, as shown. Cross the wires, then use your jewelry pliers to tightly twist the wire.
Trim the extra ends of the wire so that you are left with a 1/8-1/4" twist.
Now, we will glue the flower to the wire.