My tourney days are well behind me, but I'll share my thoughts on this and hope you benefit from them.
When I had the opportunity to pre-fish an event, I would attempt to locate multiple spots and I'd choose the order that I was going to fish them by the size and numbers of bites I got. The majority of time, I'd start out at the most productive of spots and after getting my limit, I go to the one where I'd gotten the biggest during practice.
Of the many lakes I've competed on that I was unable to pre-fish, I would get as much information as I could from maps, calling local tackle shops, checking weather history, etc, work out a game plan and then just eliminate areas when it came time to fish.
In both instances, catching a limit was my initial focus and I was rewarded with many top five finishes. I should point out that at weigh-in there would always be one or two guys with two or three nice sized fish that wouldn't make the cut because they didn't limit out. 13lb-15lb bags would put me in the money the majority of time.