A while back I made a knitted tea cozy that has been used non-stop between washings. I used acrylic yarn which is great for not holding onto tea stains but I wanted to make a back up and use a different method/medium. So I did some cozy investigation and came up with just a very basic one that I'm going to share today. I hope you don't mind.
First, sketch up a pattern, it's super easy, it will be the shape of the wide end of an egg, the width (tip of the spout to end of the handle) of your tea pot plus three or so extra inches, and the height of your teapot plus those same extra inches. Use this to cut out two layers of batting, two linings and two main pieces.
Matching up the straight edges, layer the batting on the bottom, the main fabric face up and the lining fabric face down and sew together.
After that I like to trim the batting close to the stitch line so it takes away some of the bulk.
Then I press the seam allowance toward the main fabric and flip the lining to sandwich the batting between the fabric. It will look like this...
Repeat this for the other pieces to create the other half of your cozy. At this point you can quilt the pieces as desired. Sandwich the two halves together, right sides facing, lining up the straight edges again, and sew around the curved portion. You can use a serger for this if you have one or zig zag the raw edges.
Flip it inside out and you're done. Go make a pot of tea and use your new cozy to keep it nice and hot!