Put a picture of the beach you visited in a shadow box frame and fill the bottom with sand from that beach. Much neater than a random jar of sand and shells! decorate the frame or put seashells or treasures found on the beach in the shadow box
Fill your shadow box with vintage memorabilia. Create a custom shadow box with wood trim, glass and a backer board. Have your materials cut to size at your local home improvement store, and then you only have to assemble the parts to create any.