I keep my closet doors closed and the dresser drawers closed. They KNOW they're not allowed in there.

Mitzi has taken to sleeping on top of her covered litter box I know .... very strange and not at all comfortable looking, but she likes it. I'm planning to make her a little fluffy mat/pillow to make it more comfy. Of course, once I do that she'll probably find another strange and uncomfortable looking place to sleep -- ah kids!