You can read Part 1 here...
First Stage
This is the early part of the tourney. Initially, you'll want to get a feel for the flow of the table and try to get a read on your opponents. Since players change tables so much in MTT's as the field is narrowed down, reassessing the table flow and its players is something you'll be doing throughout the tournament. I like to play this stage cautiously and identify any wildly aggressive players. Hand selection is always important, but especially so at this point of the tourney. In early position I play only the very best hole cards with no exceptions. A-A and K-K can obviously be played at anytime.
On the other hand I don't mind playing weaker hands in unraised pots with good position at this stage because the blinds are so low. Just be careful after the flop and if in doubt, fold em. This isn't the time to take any unnecessary chances even if you feel the situation presents you with a slight advantage. When I'm in this feeling out part of the tourney I generally try to keep the pots on the small side if possible unless I have a monster hand. It's probably good advice to avoid scenarios that can lead to major tournament life decisions during this time. Good players are not only good at making tough decisions, but just as importantly, they are very good at identifying traps ahead of time that can put them to a tough decision for all their chips. Be observant and stay out of trouble.
Second Stage
After the blinds have increased 3 or 4 times the game starts to normalize. Now is a good time to get more aggressive with solid hands and accumulate chips. This is a very important time of the tourney for enlarging your stack. Most tourneys are top heavy when it comes to paying out the big money so this is the time to position yourself for the long haul, unless you're just happy to finish 'in the money' which usually means winning little more than your entry fee. The time tested 'tight-aggressive' strategy is probably still the most successful MTT strategy that the average player can employ and win his fair share of the prize pool consistently. Be selective in the hands you play but play them strongly unless met with resistance coupled with perceived strength. Make a mental note of any weaknesses your opponents may possess. Isolate these individuals when possible and exploit their maladies if and when exposed. Observe how people react when tested by being raised or re-raised and look for opportunities to take advantage of it.
'Loose-aggressive' tactics are best left to the few professionals that have mastered it. Most players that use this strategy crash and burn more often than not, and end up tightening up their hole card selection standards eventually. Re-buy MTT's are the possible exception to the rule. Since losing all your chips isn't as catastrophic in a re-buy tourney, you can assume more risk in hopes of building a large stack of chips early during the re-buy period. I mean expanding your range and not just playing any two cards. The point is you can take more chances knowing you won't be eliminated on a miscalculation.
In Part Three we'll focus on the final two stages of MTT's.