We used a Target side table as the foundation for our project and all measurements are customized to it. If you’re using a different table, make sure to cut boards to your own measurements. Measure the depth between the front and back legs at this height to determine the depth for your shelf. Measure the width from the outside of the front legs and add 2 inches. This will determine the width for your shelf. Once you have these dimensions, cut the 3/4-inch-thick piece of wood to size. We used white oak. Once cut to size, line up the edges of your side pieces with the edges on the bottom side of your top piece and then move the side pieces in about 1/2-inch each. Once in place, secure with two L-brackets on each side. Sand edges, if necessary, and wipe clean with a tack cloth. Attach plywood board to the back of the top shelf using a nail gun.