Draw a scalloped pattern that measures 4-1/2" from high point to high point. This yields three scallops for an 11" length of lumber. Once you are satisfied with the spacing and shaping of your scallops, transfer the pattern to the four pieces of 11" lumber.
Plug in your jigsaw and cut out the scallops you just traced. Take your time to make sure the rounded portions are well-sculpted. Sand the scalloped cutouts to make sure the edges are smooth.
Take the two wood panels and mark the locations where the scalloped boards will be mounted. The bottom two will be mounted flush with the bottom of the boards. The next two will be mounted 8" above the high points of the scallops on the bottom one. Measure carefully, since there is little room for error.
Apply liquid nails generously to the ends of the scalloped boards and connect them to the straight boards as marked. Clamp the wine rack together and let the glue set overnight to make sure it is sturdy.
Prepare the entire wine rack for finishing by sanding it lightly all over. Pay special attention to any excess glue that might have leaked out between the wood pieces. Carefully sand away the excess. Wipe off any dust.
Stain or paint the wine rack as desired. Apply clear polyurethane once the stain or paint has dried. This makes the rack water-repellent and easy to clean.