A few years before I learned to knit, I went through a "waxed linen jewelry" phase, making little charm pouches and pen basket necklaces out of waxed linen. Around that time, my mom began freezing bottles of water to take to work. I used the same looping technique for the charm pouch to make a cotton pouch for the water bottle. I made a couple of these, stopped doing it because it was tedious, learned to knit for real, and forgot about it all.
My sister called this weekend to say her water bottle cozies have now fallen apart. She wants new ones. So I thought I might see what I could do with knitting needles. These are the fruits of my experiments over the past couple days.
Both of these are from worsted weight Sugar 'N' Cream cotton. I made the one on the right first, following this Water Bottle Tote pattern. The one on the left is my attempt at pattern refinements: a flatter bottom and less annoying stitch pattern (using Turkish Stitch instead of Purse Stitch). Both of them are a bit too small; they won't fit around a liter-sized bottle, but they'll work for smaller bottles.
I want to try again, then I'll post my own pattern here.