Made from the remnants of a failed CSM sock, I took what was left after being partially frogged, shoved some elastic through the hung hem, and hand finished the bottom.. I love how it came out.

I wrote up the pattern here – http://www.sarahspins.com/patterns/klean-kanteen-sippy-kozy/ or you can download the PDF version

And it’s also listed on Ravelry now (also with the same PDF download, if you’d like to store it in your library or add it to your queue)