The act of searching beaches for empty shells is known as beachcombing, and people have done it for centuries. The best places to find shells are beaches that are less populated. Shells don't necessarily have to come from saltwater beaches. Many freshwater lakes are inhabited by mussels that produce tiny shells. When hunting for shells, ensure that the original inhabitant of the shell is not still inside. Shells are often found in the shallow waters near the beach and along the beach where the tide has forced the shells onto the shore.
Sea shells are unique in that they provide a habitat for the creature that created it. After finding a shell, look up the creature in one of several ID guides found on the Internet. Sea shells are from mollusks and include clams, oysters and even snails. Shells come in either two pieces (clam type shells) or in a single piece like a horse conch.
You'll need to clean and preserve the shell to ensure it lasts a long time and to remove its sea smell. First remove any loose debris or sand with a cotton cloth. Next soak in a solution of half bleach and half water until the outer covering (periostracum) can be brushed off. Next, take a toothbrush and a toothpick and clean any cracks, bumps or whorls. If desired, file any sharp or jagged edges with an emery board. Shine with a bit of baby oil and a cotton cloth.
Shells can be used in many ways once they've been cleaned. Put small shells in the bottom of a clear flower vase before adding flowers to give the room a beach feel. Use larger shells as decorative accents on bookshelves or in window sills. Drill holes in several smaller shells and let children make a mobile to commemorate family vacations.