Fold a clean kitchen towel to use as a protective mitt. Hold the oyster curved side down (that’s upside down) so that when you open it, the deep shell will catch the oyster’s liquor (juices). Place an oyster in your toweled hand and your toweled hand on a steady surface. Wedge your oyster knife into the hinge that connects the shells. (Don’t use a regular knife; the blade is too thin.) Then turn the knife as you would a doorknob, exerting minimal forward pressure. As you turn the knife, there will be a slight, satisfying “pop” as the joint gives way. Take out the knife and wipe it free of sediment. Slide it between the shells to cut away the muscle that holds the shells together. Remove the upper shell. Carefully run the knife under the meat to release it.