An easy and informative instructable video for making the flowers I used is here
. Watch it to get a good idea for how to make the hair flowers.
For the bridesmaids pins, I actually only used three pieces of fabric. Rather than cutting circle shapes according to the template in the video, I just cut the fabric into flower shapes, burn all the way around the edges, and have a simpler flower. That's what I did for the red flowers. For my own hairpiece, I followed the video exactly except that I didn't bother with the biggest petals--to do so would have ended up with something waaaay bigger than I wanted for a hairpiece.
Once you've made the layers, either sew them together or hot glue them. Once the layers are all fastened together, use the hot glue gun to fasten a button or rhinestone or whatever into the center of the flower.
Now the flower is done; time to move on to assembling the hairpiece.