Speaking of Myra Piper's "Tatting", here's another little snowflake I'm quite fond of. It's a slightly modified version of motif #4 (the pattern in her book has seven points, and pointy tips like yarnplayer's snowflake of several posts ago), and is such a simple pattern with knots in sets of three that I've seen other people independently re-create it. I normally tat it as in the first picture, with large picots (loops) connecting the rings in the center, but you can also use smaller picots and get a tighter center as in the second picture - I should have made those center picots even smaller; I don't like when they bump into each other like that.
This is also a good example of how starching and blocking can change a snowflake - when I block, I pin the snowflakes out by placing a pin on the inside of the arch underneath the outside ring, so I get pointy tips, like this (I haven't starched recently so this is an old picture, which accidentally cut off part of the snowflake and had a weird background).
Myra Piper's "Tatting" is one of those little self-published booklets from the 80s made from letter-size paper folded in half, and is a collection of 47 snowflakes and stars, some her own design and some patterns which friends had sent her without attribution. It's another of my favorite snowflake pattern books.