I fish Kentucky lake and catch lots of shellcracker and the best advice I can give is that they don't seem to be structure oriented fish like everything else I fish for. To catch them you simply have to find the food......snails mainly on KY lake and you will find the fish. Many times you can actually see where they have crushed the shells when the water is down. For some reason I never catch them on mud bottoms....only on sand or gravel and I have no idea why. Also, when you are catching them shallow and the shallow bite goes away don't worry as their food hasn't gone far and neither have they. Just back out from the same areas and fish a little deeper. They will bite on a variety of things, but the key is to fish slow and if you think you are fishing too slow go a little slower and ALWAYS try to maintain bottom contact as they are strictly bottom feeders except when guarding their nests. I also exclusively catch them on brim reaper jigs.....(looks almost like a spider).

Here are the only quick pics I can find w/ some....my wife and daughter love catching them: