OK, here is my attempt to create snow. I decided not to use any preset or file someone else created, so I started from scratch.
I used the shiny fake stones shader method for creating the sparkling effect additionally to a luminous layer broke up by a very small power fractal.
I really miss the possibility to create sub surface scattering!
Thanks to Marc for his great snowy pine pack. PW: DOF, resizing and sharpening.