Jackson's book starts gradually, with the most basic of folds. You might think, "Yeah, I made paper fans in kindergarten. Let's move on." Well, you did - but not with the precision that Jackson displays, and not with the purpose behind it. The first of these folds, bordering on trivial, proceed through a graded series of variations. Again, in themselves, each variation might not look like much. Still, it's worthwile to put the time into doing each with the highest level of craftsmanship you can summon. The precision will matter in later exercises. Likewise, the habit of trying variations, of exploring the possibilities broadly and systematically, becomes essential when putting these folds (or any design technique) to use.
As the paper patterns become more complex, so does the more abstract discussion of design. Jackson discussion repetition in one or two dimensions, rotation, and other ways of building simple units into complex assemblies. And, as the designs mecome more complex, the distinction between two- and three-dimesional figures blurs. The first exercises just add creases to a flat sheet. Later, though, the sheets form spirals, boxes, tunnels, and other self-standing figures.
After discussions of linear creases, Jackson moves to more organic kinds of folds - soft curves without straight-line folds, or with very few. Even the random elements introduced by crumpling the paper have their place, especially when combined with more rigid design techiques. Even something as simple as folded paper offers endless possibilities for the artist, architect, or industrial designer. Jackson's book offers a beautiful and practical way to explore some of these possibilities.