Finally I found some use for all the sand dollars we have collected at the beach. First I cleaned them in bleach & water & than I used equal parts of water & glue to harden them & than used a hot glue gun to glue them on the picture frame.
What to do with your seashells and sand you save from vacations: Buy a shadow box frame and pick a picture from vacation that you took next to the ocean. Place the sand from that beach in the shadow box, add your seashells, sand dollars, starfish, etc. and you have a cheap and easy vacation keepsake!