Every once in a while, fish will only react to aggressive presentations. There have been a number of occasions where I'm fishing shallower water with a crankbait that dives to a target depth and I just can't get them to bite. Before switching to a different presentation altogether, I like to try dredging a crankbait along the bottom.
Let's say I'm fishing a shallow ledge in 6 to 8 feet of water. If I can't get the fish to eat a mid-range diving crankbait, I may try one that dives to 12 to 14 feet. This will cause the crankbait to dig hard into the bottom, kicking up dirt and debris.
I'm not sure why it works, but every once in a while I have to dredge the bottom like this to get the fish to react. Granted, you're more likely to get your crankbait hung up doing this, but there are ways to get it back.