Alternatives to Clay...!
Some times, finding clay might be hard depending on where you are living. And in those parts of the world, if you do find it, it is usually pretty expensive. So why not try Cement. It is usually very easy to find in stores and it is also very inexpensive and easy to work with. It is just a matter of mixing the cement and molding it to however your heart desires and letting it sit overnight for it to harden.
Sounds too simple to be true? I've actually tried it myself and I have not been spending my hard earned money on home decor since then!