I have the one butterfly die and I used it to make a mask.
I stamped th butterflies with pigment ink to fill the cut out. I then traced the outline with black and added some grey shading with alcohol markers to give depth and anchor the butterfly.
I was trying to make all the small butterflies look like lace, I think that might have worked if I had used one colour...not sure maybe i'll try it on black with embossing powder one day ;-)
For more information on The Friday Mashup! Challenge, see this