I tried out a series of Water-coloring techniques back in January... but only just now got around to scanning them.
This technique is a wash of watercolor with a bunch of pinto beans spread on top. Spread the beans over the page right after laying down your layer of color (or drop them/place them if you want to be more precise) and leave them there for a few good hours or until you can tell that your watercolor is completely dry. The beans stuck in a few places so you might have to be patient removing some of them.