this cuboctahedron print-out
hot glue gun
paint (acrylic is good)
cup of water
2. Glue the template onto a cereal box. with tacky glue.
6. Now, see one of those square faces on the model? Cut that out. Yep. You won't be using it. I dunno. Feed it to your dog or something.
7. Now hold the model in shape as you hot glue the tabs BEHIND the triangles and squares. Press together the tab and triangle/square for a few seconds to let the hot glue dry. (This was a confusing step to explain... Let me know if you need me to explain anything further, k?)
8. Once that's done, you'll notices about two or three tabs sticking out in the open square that you cut out. Those were meant to go behind the square, but since there is no square, you can go ahead and cut that out.
TADA! You have your basic shape.
9. Now comes the fun part-- painting! :D Set up your painting materials (cup of water for rinsing, paper towels for cleanup and surface protection, etc. etc.) along with paint in the colors you want and a paintbrush. Go wild! Do whatever design you want. Or if you wanted to do a solid pattern, sure! Or if you wanted to leave the cardboard as it is, that's fine with me! You do you. From this point onwards, do what you want. I went with this really ratchet-looking triangle pattern, but like I said, it was ratchet. XD
You could place it upside-down on your desk and have some very tumblr-esque decor...