Slumps are something we all deal with; I've found through the years the best way to handle them is to get back to basics. I know what my strengths are and fish towards them; I suggest you should do the same. If you are good at Flipping/Pitching, Texas Rigs, Cranks, Spinners, or what ever concentrate on those techniques. If you are good at shallow water, deep water, or grass concentrate on those areas.
I've learned to down size my tackle to just the basics, it is extremely hard to be a master of all the available techniques. I'm very good at Jig-N-Craws, Texas Rigs, & Spinner baits so I fish where I can maximize these strengths. I'm not that great with Crank baits so when in a slump I don't waste time fishing them. I don't try new techniques either when in a slump.
The most common mistake I see my students make when in a slump is with the hook set. They are not sure if they had a bite & so they use somewhat of a lazy hook set. I cannot over stress the importance of a solid hook set; speed is the key not strength. If you are a smaller person or woman use a heavier rod to gain the speed needed, if you are a larger person use a medium heavy rod to limit pulling the bait away from the fish.
So when in a slump I would look for small things to change, like timing of the hook set, speed of the hook set.