It all depends on the type of water body you are fishing. Also time of year will play a big part on locating fish in certain depths. Usually during the late fall and winter your Bluegill including the bigger ones are going to be in deep water in 15 to 20 feet deep. They are usually very close to sunken structure such as brush piles or bridge pillars. Usually a bait about 6 inches to a foot off the bottom works pretty good. If the water body is a shallow creek or small pond/lake your fish will usually hold up in the deeptest part of the pool. During spring through early fall the Gills are usually spawning or stacking by docks and structures. Just about any bait will nail em. Small flies,small plastic grubs,spinner baits,and of course the "bait of champions" WORMS. Fish can be found in water anywhere from 2 to 15 feet during this part of the year. Brush piles,tree overhangs,bridges and docks will usually be holdng some good size gills. I bank fish a lot and I usually find my bigger Gills next to some sort of structure. Docks,bridges,brush piles,and large rocks. Overhanging tree branches also are good places to fish. Adjusting your float will vary on how active the fish are. I also catch most of my fish by bouncing a worm off of the bottom. Hope this helps you out some. The more you fish the better you will get. Also study the habits of the fish by reading articles on Bluegill and asking other pan fish anglers what works good for them.