Frost Crystal Style
I really like how they look against my blue file folder. Last Christmas we backed them with black card stock for a more dramatic look. I don't know about real snowflakes, but no two of mine have ever turned out the same, and I've made hundreds over the years.
Fold in half and in half again, into eighths, triangularly. Trim off the long corner (if you opened it now you'd want to see a rough circle).
Would you rather make your own?
Fold your paper diagonally and trim off the long edge (or start with a square piece of paper).
On the CUT edge begin the shape of the snowflake, cutting it so you create points.
Then begin to hollow out the snowflake. Working from the outside edges towards the center cut varying shapes -- be sure to leave areas of the folds for connecting the parts of the snowflake. Try to leave more "negative space" than paper for a lacier effect.
When you have finished cutting, unfold the paper carefully.
I didn't do this before taking the photos, but you can press lightly with a cool iron to remove the fold lines for a flatter, smoother flake.