Well just about every predator fish can instantly recognize the smell and taste of another dismembered fish in the water upstream from him, just like a bird-dog can smell a quail. So, if you take a freshly caught baitfish and cut it into strips or steaks, and place it upstream from a likley cat holding area, you should have a catfish in abut 5 minutes or less. It's really that simple. Variables like fishing pressure, weather fronts, and seasonal habits will affect your succcess, but that is the basic recipe to consistently catch a catfish.
Without mentionting any names, there is a how-to fishing magazine from minnesota, and those guys put out how to books and videos on just about every species of gamefish in America. Checkout their book about catfish fundamentals. I went from an infrequent accidental catfish catcher, to an obsessive compulsive catcher of big cats in just one season, after getting the big cat bug. I have a lot to learn, but the techniques reccomended by those boys from minnesota have really worked for me.