This tutorial was originally posted on my DeviantArt, back in 2009. Photoshop's brush capabilities have expanded so much since then that this method is probably fairly outdated, but I still think it gives a great effect in exchange for a little patience. People still seem to find it useful, so here it is!
The stars tutorial I reference as a starting point is linked at the end.
Thanks for reading! I hope you find it useful. Feel free to save and share as you please.