I haven't heard of too many people that target bluegill. They are usually an after thought when nothing else is biting. I can't say I'm not one of those people. When I really think about it though, bluegill are pretty fun fish to catch. First off, they hit top water flies like something straight out of Jaws. Second they are plentiful. Where there's one there's usually a few more. They hang out in swarms and usually you can sight fish for them.
Sometimes an effective technique is to see one come towards your fly if it turns around, twitch your fly some. If another gill sees this and comes towards it, usually that will attract more. When two or three gills are coming at your fly from different directions the competitive instinct takes over and some will hit it I believe just to be the first to get the bug. I've seen cruising bass follow this same behavior as well. A lone bass will sometimes come up sniff a fly then move on. But 3 cruising bass will usually race to the fly and the one in the lead will hit it. In the following video I try to show how easy it is to catch bluegill on a fly. I believe I'm using a caddis but to be honest I can't remember. Any high floating fly will do the job, hoppers, popper, caddis, humpy. Something that floats high and has rubber legs will do the job. If you notice on my third cast the fish hits the fly about 10-15ft from shore.
Really most bluegill swarms aren't more than 10ft from shore. My casts in this video are really way over where they need to be. I was just trying to see how far I could cast as well as catch fish. I will try to show more movies on how ferocious gills are and different techniques to catch them. I'm no bluegill expert but I have a pond near me that's very clear and I think it will be great for demonstrating their behavior.