I was catching a lot of pickerel about a month ago when I was using non-standard retrieves on spinnerbaits to mix it up (when the bass weren't biting).
I'd let the lure sink to the bottom and bump it along a bit like a worm til I could feel a little open water. Then I'd reel in to the surface and pretend I was fishing a buzz bait for a few feet (reel fast enough to keep it on the surface). Then it would be a jerk bait (pause, tug tug, pause, reel, tug, pause, etc).......
The point is, I'd change it up several times in the same cast with whatever kind of lure I was using, and although the bass weren't generally interested, the pickerel loved it! I even had one chase a gulp minnow I'd done this with about 4 inches out of the water RIGHT in front of me. He hooked himself on the way back down, all I had to do was hold on, then lift the rod tip back up to pull him out of the river