So, I made a cat bed for my cat. I make these every now and again, because they're easy and cheap to make. Plus, the cats love them. They take about a yard of fabric, and I normally use the box that bottled water comes in as the base. I decided I would document the process here for your entertainment.
Step one: Cut a piece of fabric that will fit all sides of the box that you have.
Then serge elastic around the edges. Stretching well as you go.
Smack the cat in the head...repetedly...because she's chewing on the elastic.
Get attitude from cat.
Add fill of your choice:
Add dopey cat: Volia! Cat bed!