Just load unpacked file snowflake_brushes1.abr from brush panel, and they will append to list of current brushes. In case if this file is not compatible with some Photoshop versions, it can be easily re-created from files in folder PNG\ with Photoshop command Edit -> Define brush preset.
After applying brush properties: Shape dynamics -> size and angle jitter, Scattering - Scatter and Other dynamics -> opacity jitter, they will produce results like this:
...and they can be useful for creating seamless patterns and backgrounds in few minutes:
This brush set is free for non-commercial use (Creative Commons Attribution-NonCommercial license).
I've created a pack of 6 Christmas cards with real snowflake photos and snow decorations, using these brushes:
If you want to see more snowflakes, you can browse through all snowflake pictures.
Here you'll find snowflake photo wallpapers in numerous resolutions and screen proportions, up to Ultra HD 4K.
And here is article about snowflake macro photography.