This video is really cool, about reusing old cardboard boxes to build furniture and construction materials out of, biodegradably waterproof and all: https://www.youtube.com/watch?v=45JhacvmXV8
And it pairs really well with this video, about using 3D-printed molds and paper waste to create strong, new shaped objects: https://www.youtube.com/watch?v=0ItPfhx3ulw
(Do consider the comment which advises to let the paper/cardboard soak rather than blending/shredding, to retain the longer fibers and therefore strength)
This could be considered a form of #woodworking, I guess?