Take a ride around the lake right after dawn and see where the baitfish are hanging out. If it's shad, they'll be right at the surface before the sun shows up. That will tell you how shallow to look.
If you don't see baitfish, at 72 degrees, I'd still be looking at the main lake points and the creek channel where it joins the main lake or slightly back into a creek arm. Then work your way shallow along the creek if you don't hit anything out there.