I try to take boxes that I've gotten shipments of stuff in and use those instead of going out and buying gift boxes. Shoe boxes work well too. Wrapping presents with newspaper is another thing that we've done from time to time.

I like to wrap gifts in the comics section of the newspaper, I think it's more "fun" than standard wrapping paper, and for at least some of my friends, they're getting hand-made things from upcycled jeans.