I found this papier mâché enclosure project on the always excellent Hackaday.

I’ve gotten a bit… creative before with enclosures for my projects, but this takes things to a couple of different levels. It’s cheap, and infinitely customizable, and stronger than it looks. The only downsides I see are the amount of time required to make it, and the enclosure won’t be very water resistant at all.

If you can live within those two limitations, it’s a very clever solution.