I'm not familiar with the lakes y'all are fishing, but some of the best advice I can give about casting a jig is to slow down the retrieve. When you think you are fishing it slow, slow down some more. Another good trick is to count your bait down to find the strike zone. To do this, just start your counting as soon as the bait hits the water. Try varying counts until you discover how deep the fish are. If you are vertical fishing try fishing slow also. Make short subtle movements every so often to give the bait some action, but also "dead stick" the bait and try to hold it perfectly still. A lot of times the fish will thump when you are not moving the jig at all. Lastly, if you know there are fish there and you can't catch them, try elsewhere in a location that is similar to the one you know is holding fish. Sometimes fish just are actively feeding and unless you can get a reaction strike they may be hard to come by. You might can move to a different area and find a school that is feeding. Everyone has experienced not catching along side someone who is. It is a very frustrating experience for me and I find that its normally best for me to just move on and try and find fish elsewhere if I'm confident I'm fishing with the right bait at the right depth....hope this might help you and your son next time out! Good luck and tight lines!

CB