I got a book called <I>Drawing fromt he Right Side of the Brain</I>, and one of the exercises was to reproduce a picture, only the trick was to reproduce it while it's upside down. It tricks the left side of the brain (which is associate with logic) to let the right side of the brain (which is associated with creativity) deal with it.

The original was done by Cooner, and he knew I was using the original for this exercise. Maybe I'll show you the other one I did, but it's not too good. For one thing, I drew it too big. It doesn't fit the page!