Source: Martha Stewart Kids, Volume 8 2003
Sew seashells to swimsuits for sweet seashore style. Make holes in shells with an awl, or hunt for ones with holes already in them. Sew them to a neckline by looping a needle and elastic thread through suit and shell, from back to front and back again, then going through next shell, and so on. For shorts, knot shells to bottom of drawstrings.