Ok here is a very interesting tutorial on how to make a playing card cookie from air dry clay. It's from Japanese Fake Sweets Blog but some parts are explained in english and you can understand everything from pictures anyway
http://thikiton.blog129.fc2.com/blog-entry-199.html
I would like to ask her for permission to post this link here but I don't understand a word on this blog and I don't even know where is teh contact button there!