Depends on the condition and size of the water body. I have caught very nice Bluegill in ponds that are not that big. They are usually in the deeper parts of the pond hanging on the bottom. A lot of the times the smaller fish are the more aggressive and usually get your bait. Try fishing the deeper areas of your pond. Also I find that artificial lures such as Rooster tails,jigs,and small soft plastics,usually catch the bigger sunfish mainly because the smaller fish can't get the bait. In the bigger water bodies nice Bluegill love hanging around brush piles,docks,inside boat slips, and under overhanging tree limbs. Depending on the time of year Bluegill will be in their patterns. They are very aggressive fish and it does not take long to find out if they are in a spot or not.
Side Note: I use night crawlers about 95 percent of the time and catch some nice ones year around!
I also love using the Gulp Alive Night Crawlers.