Read on to learn how to craft your own...they were a blast for the kids and me!
My personal suggestion, ORDER your scroll BEFORE making the case. I thought my cases were big enough but after my scrolls came in the mail, I had to hollow them out to fit it! I would say use a pencil cut slightly larger than the scroll itself as the mold for your mezuzah case. You basically wrap the clay around the pencil.
Next, unless you want to run out to the store and buy polymer clay, here is the recipe I used for homemade clay (thanks to http://www.homeschooling-ideas.com)
More Homeschool Crafts
Mix ingredients in a bowl.
This clay bakes best if the craft items are not too thick - about 1/2 inch is best.
Bake your case on an ungreased baking tray at 250 degrees for 30 mins, then turn and bake them for another 90 minutes until they are hard and dry. When they are cool you can smooth them with fine sandpaper before decorating and varnishing.
For my daughter's we took some vintage jewelry pieces, her favorite shells, and pretty ribbon and covered the case. (Picture was on the blog header-top)
As for my son, he's totally the outdoorsy boy. We took a turkey feather of his dad's, gathered some twigs from outside and added a cat's paw shell to the front, which oddly worked well to put the letter Shin on.
Very easy project, and so fun! Let your personality shine when making yours for the doorposts.