This cozy fits a regular glass pint jar. Simple enough for beginners. Pattern works best in continuous rounds rather than rows, although both will work up the same.

If you don't like the magic circle, use the following as round 1: chain 4, slst into the first ch. Working into the center of the circle, sc 6. Do not slst, continue into round 2.
I used yarnspirations caron cotton cakes for the mint, as well as pink and yellow cozies. The blue and white cozy was made with lion brand basic stitch anti-pilling (standard size 4 acrylic). I used multiple yarns to show this pattern will work for any size 4 yarn.