Wade In
In late summer, the water can drop low enough that boating isn't practical. Wading in can get you close enough to fish the deep holes where the catfish wait out the heat. Stock your bait in a jar with a few ice cubes in it and carry it with you along with basic tackle. Don't worry about waders and boots; provided you don't mind getting a little wet, your tennies and an old pair of jeans will work fine.
Keep a Log
Catfish are bottom feeders that can lurk among underwater structures in patterns that can be hard to predict. Like other fish, they can also be temperamental, feeding in a frenzy one day and not biting another. To fish more consistently, keep a catfish log. Include the date and time of day you catch each fish, descriptions of the weather, temperature and wind direction, the bait and rig used, the location, depth and water clarity, the retrieve and, of course, the area of the lake or river you are fishing. If you regularly fish the same body of water, you may wish to name different locations or structures you frequent to make it easier to record and use your fishing log. Eventually, you will start to see what factors separate your good days from your bad.
Use Juglines
According to Bass Pro, juglines are a great way to catch a number of smaller cats, although they are seldom targeted by large cats. Attach a sturdy nylon rope to the neck of a 2-liter soda bottle or milk jug and attach a hook and sinker to the line so that the bait is a few feet off the bottom. Paint your jugs bright colors for easy visibility and bait them with shiners or bluegills for flathead cats or with chicken livers or other chunk bait for channel or blue cats. Drift downstream with your jugs nearby and watch them for bites. Chase after them and retrieve them with a hook once the catfish are exhausted.