it to cut the other three to the same size. i set the cut board on top and make sure the ends are flush (top left), then i mark the board to be cut on the other side (top right). in the bottom photo you can see i place the blade right on the edge of my marked line and cut.
cut the long sides the same way. double check to make sure they fit to the tray bottom by placing them around it.
sand the tray sides before attaching them to the tray bottom.
step 5: attach tray sides to the bottom.
nail through the lower half of the sides into the tray 