1 cardboard box (the size of the doll you want the bed for)
Cut the flaps off the box, save one of the shortest flaps for the next step.
Use the short flap to make a head/foot board design. Simply fold the flap in half and make half of the design. Cut your design out while the flap is folded so you get a nice mirror image, and both sides are even.
Use your head/foot board design you just cut out to trace over each skinny end of the box. Then cut out each side.
You can cut the long sides of the box as ornate or deep/shallow as you wish. Make sure you keep some of the lower sides on so the bedding doesn't slip out.
HAVE FUN, and paint your bed any color, use glitter, glue on lace, make cute designs with stencils.