One of the most popular bits of advice for targeting autumn largemouth is to work the backs of creeks or pockets where shad or other forage have migrated and attracted bass gorging for winter.
It makes sense, really, because of the changing temperatures that push bass from their summer haunts into cooler water. As autumn rolls in and the air temperatures at night help lower water temperatures, forage and predators make their way into these shallow areas. It's similar to the spring movement when shallow areas warm up as temperatures increase, prodding bass to begin eating more prior to the spawn.
Shad are a primary forage species and will make these autumn moves in large numbers, especially in Southern impoundments. They will run the banks, linger around vegetation or woody shoreline cover and ball up in the middle of creek channels providing bass ample opportunity to fatten up. When water temperatures hit about 45 degrees, the shad start dying.