Shelling success hinges on timing. The optimal window is low tide, when the water recedes to reveal expansive stretches of sand and tidal pools where shells accumulate.
Check local tide charts (NOAA or tide-forecast apps) for exact low-tide times. Bring a mesh bag, wear water shoes, and scan the wrack line (the debris line left by the last high tide). Remember to leave live shells and inhabited shells behind—many beaches prohibit collecting live specimens.