The most pervasive appetizer tradition is to center it on seafood. There is a logic to this: Seafood is light, much of it can be served cold, and you can use intense, palate-perking sauces.
Louisiana seafood is a great resource for creating appetizers. The number of oyster dishes alone is dizzying (as I will prove shortly). The local crabmeat is almost absurdly delectable, even when eaten straight out of the container. The three major varieties of shrimp are all the equals of any other in the world.