I found this idea online, and it is how to make a cozy little kind of tent for your cat, and it is made just using every day items that you probably have around your house.
You will need two plastic coat hangers, some wire, a small cushion or pillow (like a throw pillow) and a large tee shirt.
The clothes hangers are wired together for the frame of the tent, then the pillow is put inside and everything is covered with the tee shirt. the neck of the tee shirt is where the cat goes in and out; and the bottom part of the shirt is tied together, closing the back of the cat tent.
Here is the directions and pictures, so you can see how to easily make one of these for your cat.