Blue crab is an important part of the Gulf Coast economy, particularly in Louisiana. The commercial fishing industry harvests blue crab for restaurants across the country, but you do not need to be a commercial fisherman to have success catching them. Many coastal Louisiana people catch their own fish, shrimp and crab to feed their families.
Just about any meat scraps will do to catch blue crab but expensive meat is not the best. Blue crab enjoy chicken or turkey scraps, particularly organs or necks. These are the least desirable parts of the bird so you can likely get them from your butcher cheaply. Blue crab also enjoy shrimp, and in Louisiana you can catch shrimp easily for inexpensive bait.
During particularly hot weather, blue crabs in Louisiana tend to hide in the marshy bayou areas. Blue crabs are most active early in the day or early in the evening, when the weather is cooler. Moving tides are a good time to set out crab traps because the blue crabs will be moving from the estuary grasses into the open waters to feed. When the blue crabs find your baited traps, they will eagerly head towards the easy food.
Commercial crab fishermen use large crab pots or traps to capture large quantities of crab. Use smaller versions of the commercial traps in the bayous of Louisiana. They are easy to use; the bait rests in the center of the pot and the crab crawls in but cannot leave again because the opening works only one way.
In reality though, if you are catching blue crab for your own personal use, you do not need anything more elaborate than a fishing pole. Bait the hook with chicken pieces or bits of shrimp and wait for the crab to come to you.