I think I'm in love with this shape from the Silhouette Online Store!
I have been making paper snowflakes for the past 40 years. I have put together a tutorial for folding and cutting and patterns for 9 of my favorites. This PDF file gives instructions and full sized patterns to make 9 snowflakes. You can use your imagination and make your own design with the same methods. The patterns call for 18 inch square paper and finish at about 16 or 17 inches round