You will need;
Fleece (around 90cm by 25cm)
Fold the top top part of the fleece over (right sides together) Using the mark as a guide to where to fold.
Now fold the bottom up, using the mark as a guide.
And there you have it. One fleece cover with no fastenings to catch yourself with. WARNING time! DO NOT FILL YOUR BOTTLE WITH BOILING WATER. Bottles can leak, so don't use water hot enough to scald yourself! This may seem like a very simple cover, but I still believe it's the best. Brighten it up with some festive fleece or other fancy patterns.