This is
a step by step, while I was doing it, account of how I made the butterfly on Arlene's BB&B RR block.
I began by tracing a picture of a butterfly onto tracing paper. I cut away the wings from the body and tacked one wing onto two layers of a silvery organza ribbon. I think that the ribbon was actually a bit metallic.
Next I used a piece of the wire that I took out from the edges of the organza ribbon. At the point of the wing where it would join the butterfly body, I couched down the wire following the edge of the paper. I left a tail of about 1 1/2" at the beginning. On the first wing I used white thread to couch with, on the second wing I used pink thread which didn't show afterwards because I used pink embroidery thread. 
I used a single strand of a shiny rayon thread which I ironed flat first, and buttonhole stitched around the whole wing removing the paper pattern as I went along. The tails of wire were a big nuisance, and I tried taping them down with Scotch tape to save my thread from forever getting caught.
I completed the buttonhole stitch and then did a little bead embellishment.

I added a bullion body and poked the wires through the fabric to the back, where I anchored them firmly. I will sew a little piece of ribbon over the area with the wires.
I added the felers and a bead for the head