I bought these feather butterflies from a pound shop! One day I decided to finally use them! I bought a small sinamay hat base from Abakhan, I think it was about a pound. I used my E6000 glue, which should work they haven't fallen off yet! I spent time arranging the butterflies so they appear to have 'landed' on the hat base. To ensure they stick to the base, I held each butterfly onto the firmly for about a minute. Unfortunately I only had eight butterflies! ten would look better. I think this would quite gothic with black butterflies or orange :-) A piece of veil is also a good alternative!
I glued a hair slide underneath the butterflies to avoid glue being visable.