Basic knitting plus knitting second stitch over first
simple single crochet
A fun rib-stitch makes this tea pot cosy a bit out of the ordinary. It won't be hard to alter the size to fit teapots that are larger or smaller, and the stitch is very stretchy. A darker color will minimize any tea dribbles.
5 st per inch over pattern 4.5 st per inch over stocking stitch