How to do it
Paint inside and outside of wood veneer box and lid with craft paint of desired color and finish. Set aside and let dry completely.
Using white glue, affix a border of sea glass and/or small shells to the perimeter of the lid.
To create design for lid, organize shells, sea glass, and other beachcombing finds as desired. (Tip: To keep your design secure while working, lay out shells on an index card covered with double-stick tape.)
Thoroughly mix together 1 cup sand, 1/4 cup water, and 1 tablespoon white glue and flood inside lid border with mixture. (Tip: For a specific shape, flood inside of desired cookie cutter with mixture and carefully remove cutter.)
Transfer organized design to lid, pressing shells into sand and glue mixture. Let dry completely.