I'm going to agree with Michele on this one. If 3rd is where the cash starts, play up until that point to make it to the money (if that is in fact the OP's objective) after which time you can chnage gears and give em he'll.
Like HoldemChamp said, there isn't going to be much advice out there more sound than that of Howard Lederer, he is the man. Why risk busting out before the money? Secure your position in the cash, protecting your bankroll, then switch it up and let some of that agression out on the other two finishers.
Would I play like this every time? Probably not. I like to be on the big stack too much, and dictate the action.