Cut the opening flaps from your 2-foot and 3-foot cardboard boxes.
Flip both boxes over and tape their bottoms securely closed with packing tape.
Measure diagonally across the bottom of your 2-foot box from the bottom right corner to the upper left corner.
Cut two pieces of scrap cardboard to the measured width and 2 feet long. For instance, if the diagonal measures 14 inches, you need two cardboard pieces 14 inches wide and 2 feet long.
Cut a 1-foot slit lengthwise down the center of each 2-foot cardboard sheet.
Slide the slits together to form an X.
Fit the X inside the 2-foot box. It should fit snugly.
Create a similar X for your 3 foot box. These Xs are the supports for your desk.
Draw a zig-zag of hot glue over one of the sides of your 2-foot box and press the 3-foot box into it, securing the two together. This creates a low seat for you to sit on with your legs facing front. To write, turn to the side to reach the elevated desk top.
Cut cereal boxes in half and reserve the bottoms.
Glue the shallow boxes and plastic cups around the upper edge of your 3-foot box. They will be holders for desk supplies, notes and lightweight notebooks. Allow all hot glue to dry overnight.