I decided to do this as a pic-tutorial!
A few notes before starting:
Make sure to empty a small amount of clear polish from the bottle if its new to make room for the powder!
Eye shadows with shimmer and glitter will obviously create a shimmery polish. It looks almost like satin.
This can be pretty messy. I did mine in the bath tub (not while bathing, haha).
Of course the polishes aren't going to be super high quality like your expensive name brands, but they're pretty awesome and fun to make! They last well in my experience, dry quickly, and look pretty good! To pump up the shine use a glossy top coat, or keep the satiny finish with a matte one.
Have you made colors before? What method did you use?
Feel free to share your creations and experiences at http://www.facebook.com/mommiesmanis