Wrap your string around the elastic and insert it through the back of the button shank loop thing. Pull
Follow the directions on the box to cover the button. On the bigger buttons you can put a layer of muslin in between the button and the cute fabric. I highly recommend doing this so that the metal doesn't shine through the fabric. (I tried doing this on the smaller buttons, but it doesn't seem to work - too thick.)These make great, inexpensive gifts (especially if you can use a coupon at Joanns or check on etsy. Beware: these are very addicting to make!