Threadfin shad make a difference. So do insect hatches. If you don't have insect hatches such as mayflies, damselflies, and dragonflies, add habitat for their nymphs. Rocky habitat such as riprap works well, so does submerged wood.
Feeding fish at the surface, as Frank's recommendation above, can also make a difference. Even though your bass may not eat fish food, they'll tend to chase those fish which do.
