To lay out the design, use a pencil and a ruler to transfer plans
to the real size on cardboard. Be careful to make the corners square (90°).
Use something like the edge of a square piece of paper, or a book, or a
protractor. Notice that one edge of each side must be moved in a little
(the width of the cardboard) so the glue tabs will fit inside the box properly.
To cut the piece, use a ruler for a straight edge to guide the knife.
DO NOT cut directly on a table top. Use a work-board or cut on top of a
scrap piece of cardboard. Make the first cut carefully and not very deep.
This first cut will work as a guide for another pass or two to finish cutting
all the way through.
To score the piece where it folds, draw the fold line on the
back. The piece will fold in, away from the score. Line up the straight
edge along the fold line you drew and carefully cut through only one layer
of the corrugated cardboard. The cardboard will now fold neatly along this
half cut.
To glue pieces together, use hot glue. You must work quickly because
the glue cools and hardens right away. Apply the glue and press the pieces
together. They stick almost instantly.