It really depends on if you were able to pre-fish any other time. If you were, than I believe it's about hitting the areas that you feel "should" hold fish but didn't hit them in your previous trips. Should you find some fish, leave it alone and add it to your list of spots to hit. You should have 3-5 spots you are confident in.
If the day before is your only day to practice, I think you should do map study before hand and find spots that should hold fish for the season you are in. Once you have those spots, go to them and throw lures that will cover all levels of the water column until you get bit. Once you do, leave and try another similar area and see if you can repeat what you did. If it holds true you just discovered a pattern to use. If you don't find a pattern, I would fish where the fish "should" be and work hard. If you start finding fish in an area, don't over fish it as you will need it in the tourney.