Measure the length and width of a sturdy cardboard box. Alternatively, use a wooden crate.
Cut strips of cardboard that equal the length of your box, using a sharp utility knife. Cut a second set of strips equal to the width of your box. Make the strips 6-inches wide.
Mark each strip at 4-inch intervals.
Cut a slit halfway through each strip at the 4-inch marks. Make the slits 1/4-inch wide.
Place the lengthwise strips inside the box with the slit opening at the top, spacing them 4 inches apart. Slide the widthwise strips over the lengthwise strips with the slit opening at the bottom. Connect them by sliding the corresponding slits on each strip into each other. The strips form a grid of compartments, with each compartment able to hold one glass.