Fit the upper and middle crosspieces into the gaps in the legs (the middle ones act as armrests for the bench). Secure them by toenailing 3-inch screws through the crosspieces and into the inside faces of the legs. Cut 1x2 lattice strips to size, per the cut list. Center the longer vertical strip between the bench's legs, and attach it to the crosspieces with 1¼-inch screws. Center the shorter strips vertically and place them equidistant from the long strip and the leg. Attach to the crosspieces with 1¼-inch screws. Repeat on the opposite side.