Here are some general thoughts on single table Sit and Go tournaments.
I will break the game down into 3 segments similiar to chess, early, middle and end game. We will focus on number of players remaining and blind levels.
Early Game: Low Blind levels and most or all still playing
Middle Game: Mid blind levels and about 6 players
End Game: Higher blind levels and 4 or less players
Early Game: Be very wary here when buying pots and over betting. There are always 1-3 players in the early game more than willing to call a bet even if it is 25% of their stack because they love ace rag or any flush possibility. They may even have some idea of position and will try to exploit it. You can not bet enough, without totally overbetting, risking your own stack against the early outers. Patience is key early, stick around, play the better hands. Usually at least 3 people are gone by the end of the third blind level, then the real game begins.
Middle Game: Now we have 5-6 players left and by now you should have some understanding of the remaining styles of play (if not, you are not paying enough attention, even if you are wrong, try to put a label on a player, you can always change your opinion as the game progresses). You can try to buy a few pots in the middle game, especially if you were patient early on, the better players will put a tight label on you, this is good. Be selectively aggressive in the middle game, there should be less players willing to pay just to continue. Play the player more now that you have an idea of what they may be up to. Patience is still warranted here as you do not need a mountain of chips to survive to the end game.
End Game: Now there are 4 or less players left, if 3 or less, you are in the money and can really open up your game if desired. If 4 players are remaining, you should still open up your game. Now is not the time to be patient, increase your aggression. Many players will play very tight now as they envision themselves cashing since the bubble (payoff cutoff) is present. You can explioit those players by being more aggressive in the late stages. You really should be playing for first or second, the amount of money made for first and second will make up for the fourth place finishes.
Single Table vs. Multi Tables:
The 10 times big blind rule goes out the door in a single table tourney. I prefer not to push my entire stack until I am down to about 5-7 times the big blind. Unlike a multi table tourney, there are no outside monster chip stacks to contend with, what you see is all the chips in play. If one player is way out in front this is good, it places all the other players in the same boat. When there is a big leader you can step up your aggression against the others like you were in the end game. You can even get a little brave against the chip leader if there are many players left as they will want to hold on to the chip advantage as the field shrinks. In a multi table tourney you will play most of the game at a full table. Single tables obviously shrink each time a player drops, thus your play must adapt faster.
These are just general rules to follow. We all must give and take in order to learn more and improve our games to win more cash. In poker every situation and game is different and must be treated accordingly. Extremes happen, I was once in a single table tourney with all 9 players ramaining after an hour and twenty minutes. Tightest table I have ever sat through. Also have been down to 4 players within 15 minutes and played 4 way for the next hour. The other day I was heads up against this player and the blinds were only at 75-150 (1500 start). Needless to say, we played heads up for a while.
Develop your style, tweak it as you play / learn and you will find single table prosperity.