Found this tutorial at Maize in Montana. So great!
You'll need a strip of fabric, needle and thread, scissors, button and a pin back (can also use a large safety pin).
Pick out some fabric you like which frays really easy. Depending upon how big and thick you want your flower, cut a strip of the fabric. Mine is 1 inch wide and 44 inches long. If you want your flower smaller, don't cut it as long or as wide.
Flip it over and start a running stitch along the bottom of the strip of fabric.
Shape the fabric into a flower.
Secure all the layers by stitching through each and securing on the back.
Next, stitch the button in the center.
After the button is secure, stitch on your pin back or safety pin.