Cut wood to size. With a tape measure, handsaw or circular saw and square, cut one side piece and one end piece from two four-foot, one-by-ten-inch pieces. Then from a single six-foot, one-by-eight-inch piece, cut the lid to desired size. Cut the bottom out from the plywood or particle board.
Find a flat surface to assemble the toy chest, then screw six corner braces in place on the box's bottom (two on each side and one on each end). Make sure the braces are flush with the piece's edges. Screw the end pieces to the braces at the end of the bottom piece, and then do the same for the side pieces. Next, attach the four upper corner braces that will attach the sides and ends to each other. Lastly, put the lids in place (even with the ends and sides) and screw the hinges in place.
Some people don't want their children coming into direct contact with bare wood, so they put a couple of layers of paint on the box. The best way to paint the box is to first assemble it, then disassemble it and then paint it. This will prevent splinters and other wood-related injuries. Other options are handles, so your child can easily open the box. Handles can be made out of a number of things, but rope is one of the more popular choices.