I think they are fairly easy. Take a strip of fabric (looks like she used a chiffon fabric to me), fold it in half, and run a basting stitch (a long running stitch), or on a machine with the stitch length set really long, down the side of the strip close to where the two edges meet. Gently pull on the stitch till the fabric gathers and ruffles. Then it looks like she sewed the strip into a circle making the flower. Add a center button and your done.
Let me see if I can find a tut in my huge list of bookmarks
This is how I make them.