Making "Pop-Up"

I've always enjoyed pop-up books and for several years I thought it would be fun to make a pop-up New Year's card. I've had this book about how to make them on my wish list for years but, even with its instructions, the kind of pop-up cards I wanted to make seemed like they would be beyond my skill. Why? Because I like puzzles and wordplay and all my ideas were complicated interlocking letter designs that are evocative of MC Escher and therefore quite difficult (at best) to construct.

So I have kept the idea on the back burner for years.

But one day about 4 months ago a pop-up card showed up at our office. It looked like this:

It was truly remarkable. It was a card that lay totally flat, yet when opened revealed an intricately designed willow tree. I couldn't take my eyes off it.