I traced the shape of the pillow (standing on end) on a paper and used it as a pattern for the ends. I measured around the entire pillow to get the length of the main part of the fabric. I had to do some easing to make it fit together. I did not use a long zipper like the ones that come on the pillows - I used buttons on the back instead.
I wish someone would sell pillowcases for these pillows as mine was awkward to make and difficult to use.