you just need regular old acrylic craft paint, a nice stiff-bristled brush, and a stencil. the problem is, i didn't have a snowflake stencil...or so i thought... until i was cleaning up the scraps after punching & diecutting snowflakes out of patterned paper, when i realized, YES, i did have an unlimited supply of snowflake stencils!!! (score!) :)
i really did use those scraps for the card i made above, but to make the demo easier to see, i punched a couple of "stunt flakes" out of red cardstock. (if you're punching-to-order, i recommend glossy cardstock since it holds up really well to repeated coats of paint!)
work from the center out, to avoid ruining the snowflakes you've already done. if you want them closer together than you can get without smearing, either allow the paint to dry between coats, or punch more than one flake on your cardstock and stencil them all in one go!
as soon as i was done i had to go and look at ALL of my punches and dies...and suddenly they were all potential stencils! give this idea a try and i bet you'll do *EXACTLY* the same thing afterwards!!! :)