To open oysters in the traditional way, wrap a dish towel over one hand for protection. Place an oyster, rounded shell down, on a board and press down firmly to hold the oyster in place. Using an oyster shucking knife, which has a short, thick, pointed blade that will not break under pressure, place the tip of the knife at the base of the 'hinge'. Twist the tip of the knife firmly to work it between the two shells, then lever the blade upwards or twist it to break open the 'hinge'. Slide the knife under the top shell to remove it and release the oyster.