The Pilgrims watched Native Americans gather lobster and clams and prepare them on the beach. They dug a sand pit and lined it with hot rocks and coals. They added the lobster and clams to the pit and covered them in fresh, wet seaweed and more hot rocks, steaming the lobster and shellfish in seawater.
If digging a clambake pit is not your thing, just go ahead and get a big pot and steam or boil them. They will be just as delicious. Most important, make sure they are fresh.