Do any you have tactics that exclude the small bluegill? I have one that seems to infrequently catch bass and bream: Carolina rig a live night crawler and reel it in slowly this will usually catch a teeny bass or a nice gill. This works well but I'm interested in what you do.
I tend to use artificial baits as well. Twister tails and nymphs in the 1- 1.5 inch range tipped with a Crappie nibblet unless Berkely Powerbaits which have there own stink. You will catch some Bass with this set up as well as gills so be ready.
Bluegill tend to school with fish of the same size. If you are catching small ones move into slightly deeper water, you may find bigger fish there. The Bull gills tend to go deeper in the summer months drift fish till you find some larger ones and then anchor up.
Tight Lines
Rob