Constantly reevaluate - reevaluate - reevaluate.
As the tournament moves along and you continue to move tables you must reassess your situation constantly. It is not entirely proper to pre-decide how you are going to play the beginning or the end without knowing the circumstances of the table you are at - stack sizes, aggression levels, number of players, etc. Do not think of it as a marathon running race, but rather a La Mans car race. The difference being the runner can have a predetermined strategy going in to the race about where he wants to be and how hard he wants to run at different points and that will work pretty well for him as conditions will not change a whole lot the whole way. The race car driver does this too, BUT he must react to the conditions of the road moment by moment (sharp curves, pot holes, gravel, etc.) and pretty much use all the gears he has to negotiate the track that is constantly giving him new things to deal with. Be aware of your environment and table conditions and when an event happens - someone gets knocked out, someone new comes to your table, you get moved to a different table - reevaluate your conditions and respond by shifting gears to an appropriate strategy.