Print out copies of your Fourth of July menu and decorate them with holiday motifs or drawings. Roll them up and tuck them into the necks of small glass bottles; place one at each setting.
Collect different seashells and use them to hold salt, pepper and spices or lemon wedges.
Take red-and-white-striped fabric napkins and partially dip them into blue dye. Set a starfish on top of each for an original stars-and-stripes look.
Buy name tags (or cut out your own), then stencil your guests' names on them in blue ink and tie red twine in the punched holes.