At the beginning of the game there are many bad players, as they go falling the game begins to become more difficult.
It is advisable to play tight at the beginning of the tournament, and to begin to force more as it gets closer to the end, the range of hands tends to change according to the moment of the tournament, however it is better that the player has the ability to change his game in accord of the tournament variables.
So, if you start playing loose, you have a good chance of getting a good stack early in the game because of a lot of weak players, but if you come across a better player, you're more likely to lose.
Close to the ITM is the time when many players will try to play more agressive and take advantage of players who are folding their hands to get on the ITM, and after the ITM these shortstack players have the tendency to shove more often in the intention of double their chips, for being in the ITM and do not care so much about losing, the intention is to accumulate chips to try to get in the best positions.