You will need to have a basic knowledge of crochet to make these.
a bottle, 1/2 skein cotton yarn and a size .5 or .6 needle
1 You will be making a flat disk that is almost the size of the bottle's base.
2 To make a circle you will need to make a chain of 7 links. Then connect the circle by making a single crochet stitch in the first chain link.
3 The first row will be 2 stitches in each link. The second + row[s] will be alternating between 1 single crochet stitch then 2 single crochet stitches in the second. Repeat until the disk is the size you want.
4 Once your circle is the size of your bottle's base, begin the next rows with only 1 stitch in each.
You will do that over and over until you've reached the height you want for your cozy.
5 Cut the yarn, tie it off and weave the extra back into your cozy.
For those who would like to know the how-to steps, here you go!