Best spots for handline fishing are mixed sand and turtle grass bottom, with sea fans and scattered clumps of man sized single corals. Far away from real solid coral formations. The fish feed and hide by ferns, or coral clumps and forage over the turtle grass. If you can locate where currents twirl because of tidal flow and meet and cross because of coral reefs some hundred or more yards away, you will also do good for bigger fish. Snorkeling is a good way to check out a spot.
Fish tend to congregate in spots, very narrow circles.
Usually because of current causing feeding patterns to fall out from floating microscopic larvae. Not discernible to the human eye, but these concentrations are where the schools stay. Fish are intelligent. You use a trolling spoon and get one or two bumps without a catch, you might as well give up, they have told everybody else. Fish bait is best for towing.