I used bits and pieces of cotton yarn. Didn't need much. For some people a little big, but for me, I think it turned out just the right size! After using a spray starch to shape and stiffen the petals, I used the fabulous E6000 glue to attach a simple hair clip.
This project took absolutely no time at all. Reading and figuring out the pattern took the most time. More of these hair clips coming soon. Maybe I will make all 100 flowers from the book?!?