River smallmouths don't always follow creek channels or other underwater structure. Most of the time, when you think they're following that stuff, what they're really doing is following the baitfish.
I have a new tactic for you — one I'm pretty sure you've never used and maybe even one you've never thought of. It starts with a big spinnerbait, which most smallmouth anglers don't consider for their summertime fishing.
First of all, we should cover the best time of year to use the float-and-fly. After years and years of using the method, I've determined that it works best whenever the water temperature is below 55 degrees.