Seashells: One of the favorite and most commonly chosen cake designs for weddings are ones that include seashells, either as the key element or as accents to the original design. The motifs can be created from marzipans, icing, molded chocolates, or simply from other candies. You can team up your seashells with other underwater creatures such as colorful sea urchins, corals, and fish. Complete your ocean floor look by scattering white chocolate shells, sand dollars, and starfish on each of the cake tiers.