Cotton Theory was developed by Bonnie Cotton. You can find a couple of the books on Amazon, and some episodes of how she does it online, as well. It is basically a unique quilt as you go method.
The teacher assures us that the more you use and wash the rug, the better it feels.
A couple ladies in the class were shocked that I would use such light colors on a rug, but hey - it works, and we don't wear shoes in the house anyway.
This gives you an idea of the quilting and texture on the top of the rug.
I think it would be fun to do a Christmas one. I certainly have enough fabric to try!