Pre Fishing strategy - when to hook em, when to leave 'em.

One thing I've really had problems with is knowing the right way to approach pre-fishing, and was hoping some guys would weigh in with their thoughts. For me, I'm generally trying to fish fast and cover lots alot of water with spinnerbaits, crankbaits, lipless and jerks. Problem is it's really hard to do that and not actually stick the fish. On lake Washington prefishing for NWBass this year, I was scouting an area for largemouth, burning a spinnerbait super shallow, and I caught a 6 lb largemouth and then immediately wondered whether or not it was fluke so I kept fishing. 5 minutes later I hook a 4.5 lber and then decide that's good enough for me and I leave. Of course tournament day comes, and I go to that area and practically dislocate my shoulder throwing spinnerbaits and no fish are to be found anywhere in that area. So I guess there are 2 parts to this question. 1) Do you generally avoid sticking any fish, if so how do you prepare your baits (bend trebles back, remove barbs etc.,) 2) How do you decide whether or not the fish you found were a fluke, without burning the spot out during pre-fish? Sorry for the long winded question but thanks for any suggestions.