Here I've bent up all the flaps, and I've scored the sides, front and back as well. This scoring should be the most painstaking part of the procedure; you don't want to score too shallow or the bending will be difficult, and you don't want to score so deeply that the bending causes breakage. Shoot for about halfway thru.

The bends on the rest of the flaps are a lot more precise, without any buckling of the sides. I bent them using a high-tech device called a "brick."