Stuff I guess

1.

Draw the layout of the cube on the back of a fake oreo box from Aldi. Other varieties of cardboard might work as well but I haven't tested any.

2.

Cut around the edges. Using scissors instead of a knife might make the process more painful.

3.

Crease along the inside of the bends. Ball-point pens work great for this!

4.

Add two-sided tape.

5.

Carefully remove the protective paper from the tape and fold along the bends into a cube.

Optional: you can add in a little Gojo Satoru if you do not trust the recipient to follow instructions and not open the box.

6.

Add eyeballs, 21 of them. I used the sort of tiny plastic balls that are inside fountain pen ink cartridges.

I also used the kind of glue that is generally associated with sniffing, because that's what I had at home. No, I will not elaborate.

7.

Tape them down with thin strips of papers in the shape of eyelids for extra security and style.

8.

Paint the eyeballs white. I used nail polish to achieve extra shininess and smoothness.

9.

For the irises, I used a combination of posca markers and sparkly blue nailpolish, but any combination of sufficiently blue and sparkly paints that stick to plastic should do.

10. Finally, I painted the rest of the cube with chalk paint (a mix of acrylic paint and baking soda) to achieve a sort of contrete-y look and mask imperfections, but for a smoother metallic finish, again, nail polish or simple acrylic paint will do.