Go down to the local garden center and get yourself a sturdy wide-tines D-handle 'compost fork (~$18), a five gallon plastic bucket (~$4) and a set of rubber boots (~$16). That's the kit in Florida and Atlantic coast up to Maryland in warm weather. Cold water might persuade you to invest in rubber gloves.

You look for quirts and bubbles to locate a likely spot, bot the fork in, pry up and use the fork to spread the block of mud and sand out a little. Then to set the fork aside and taking a wide stance, tapping your toe is optional, you set to plucking the clams and tossing them into your bucket. Wash, rinse, repeat.

In good clam areas a couple minutes work will collect a meal for two. I've seen semi-professional beachcombers/surfer/bums spend a few hours a day digging clams and selling the results to vacationers, cash goes for beer, wax and suntan lotion. Dig, sell, surf and get by three months a year that way.