Now that you've made the adorable costume, here's now to make the hair accessory.
Cut a circle with about a 6" diameter.(I traced around one of my cereal bowls).
Use a running stitch around the outer edge of the circle to gather.
Use the small amount of dyed batting you saved out and put in inside the circle.
Pull the gather until the opening is closed. Secure it closed.
Place a button in the center opposite to the opening and hand stitch it in place going all the way through the back. Attach to a hair clip with hot glue.
Add to your costume and it's a complete set!