Oysters grow in marine environments. The varieties that you can buy are always farmed. Usually you buy them by the (half) dozen. Count on two or three per diner. You can keep oysters for a good 4 - 6 days in your refrigerator.

Of course, you could cook or steam oysters; James Martin even deep-fries them in a batter! But a unmissable experience is eating them raw. The hard bit is shucking the shell. A must-have utensil is an oyster knife.

Below is a good instructional video clip that demonstrates how to open oysters, or shuck them, as the proper term is.

As you will have to exercise some force to open an oyster, better not do this standing by the sea, as Jason Hill did, but use a stable workspace. 

Pro tip: make sure to keep the oyster level while opening. That way all these lovely flavors of the sea are retained. Usually oysters have a flatter side and a rounder side. Make sure to keep the round side down.

One the upper shell has been opened and removed, check for grit and loosen the oyster flesh from the shell. Serve the oyster in the shell. Some people prefer a few drops of lemon or lime or a vinaigrette (some examples here). My personal preference is a few drops of Tabasco. Enjoy this excessive luxury!