Arrange the two 8-inch 1-by-3 boards and the two 10-inch 1-by-3 boards to form a square frame for the top of your stand. The cut ends of the 8-inch boards should touch the inside edges of the 10-inch boards, creating a frame that is 10 inches square. Make the corners flush. Hammer a nail through the 10-inch boards into the 8-inch boards at each corner.
Place the 12-inch-square board over the frame, centering it evenly so that it extends 2 inches beyond each side of the frame. This square board will serve as the top of your stand. Nail the square board to the top edge of each side of the frame. Flip the unit over so that the plant stand's top is resting upside down.
Stand a 2-by-2 board upright and set it into one of the inside corners of the frame. Secure the 2-by-2 board by nailing it to the 10-inch frame board. Repeat this step to attach the other three 2-by-2 boards to the frame. The 2-by-2 boards will serve as the legs of your stand.
Slip the 1-by-6 board between the legs of the plant stand so that it is level and evenly touches all four legs. Position the board 4 inches above where the legs will touch the floor. This board will serve as a lower shelf. Hammer a nail into the board through each leg of the stand.
Turn the plant stand upright after attaching the lower shelf. Sand the entire stand to smooth out any splinters. Apply a wood stain or paint in the color of your choice, using long strokes. Let the plant stand to dry for three hours or more before setting plants on it.