How to make a window look covered in ice crystals

We've all seen fake snow that can be sprayed on windows, trees, etc., but did you know there's also fake ice crystals? MTFX demonstrates above.

I learned about it on a shoot about 15 years ago. It works on any window, but the prop person who showed me how to use it said it works best on a freshly-cleaned dry window where the glass has been gently warmed up with a hair dryer. — Read the rest