Play fast and loose
Taking it slow is out the window: Where 10-handed (or ring-style) tournaments reward patience, shorthanded tournaments play fast and loose. This is because the blinds are coming around at a relatively quicker pace. For instance, at a six-handed table, a player is forced to contribute to the pot as a blind bettor one-third of the time (two out of the six hands he is dealt per round will be as either a small or big blind). On the other hand, a player is only forced to partake in the action through the blinds one-fifth of the time (two out of 10 hands) at a traditional table. Therefore, action is forced almost twice as often at short tables! For this reason, patience is both inappropriate and unprofitable in shorthanded scenarios.
Get used to variety
Beauty is in the eye of the beholder: A player will have to become comfortable with a wider variety of starting cards to succeed at short tables. The ring-game luxury of waiting for more premium starting cards is not similarly bestowed upon shorthanded players. Since shorthanded action is more frequently forced, the minimum bar a hand must pass to become playable is far lower.
This works in tandem with the fact that, with fewer hands dealt, the average caliber of a hand in play at a short table is lower to begin with than that at a larger table. Think about it: The odds that your opponent has pocket aces is lower at a short table since there are only five opponents to worry about, rather than the nine you will face in a ring game. Therefore, don't be afraid to play that A-8 off suit in second position (a play that is not normally recommended at a full table) -- you simply cannot afford to wait around for prettier starting cards.
Play passively at first
The importance of foreplay: Shorthanded play allows an attentive player to extract a lot more information about his opponents much more quickly than at a traditional 10-handed table. This is a simple result of the fact that with only five (or fewer) other players at the table, he will be witnessing the actions of his tablemates more frequently. Moreover, he will more regularly be able to play each of his opponents personally, thereby extracting even more information. A player's goal should be to acquire as much information as early -- and cheaply -- as possible. Therefore, I play more passively than normal for the first 20 minutes at a short table. Why pay to extract the information that I can garner for free by observing the forced play of the others at my table?
Furthermore, I want to delay the acquisition of information by others about me for as long as possible -- and, ideally, until I can decide the sort of image and style that I should project to most profitably exploit the nature of the particular opponents I am facing. This strategy is specifically tailored to short tables.
Full tables allow for players to be very selective about the hands they choose to be involved in; thereby greatly lengthening the amount of time that I would have to spend as an observer to have the same quantum of information about my opponents that I would have very quickly at a short table. And, in a full ring-style tournament where timed blind levels are the major constraining factors, I do not have the luxury of a time surplus to make this as effective a strategy as it is at short tables. So, the best way to succeed when you are short is to start slow and increase speed as your stack increases and as you learn more about those you are playing with.
It's all about position: On average, more flops will miss most hands at a short table, given the weaker nature of the cards a player is forced to play in this setting. As a result, a player in a later position will most often have the strongest likelihood of taking down the pot. This is because position merely translates into an advantage in information: The last to act has the most information available to him when he is forced to make a decision. Given this, when the players in front of you have demonstrated weakness in their actions (by, say, checking into a multi-way pot on a flop containing a flush draw), do not be afraid to put in a big bet in an attempt to win the hand. Not only should you exploit position when you have it, but you must also beware of those who are attempting to use it against you.
Get to kow your tablemates
Don't take an animal lover to the zoo. The importance of knowing your tablemates is that once you have acquired information about the players at your table, tailor your behavior to their individual styles. If your opponent is passive, you want to apply pressure by raising and betting into him. If your opponent is scared (or playing above his bankroll), do not be afraid to make oversized bets in order to make him think his tournament life is at stake. If you face an inexperienced player, you want to exploit her lack of knowledge about shorthanded play by representing stronger hands than other, more experienced players would be willing to give you credit for at a short table.
Finally, if your opponent is loose or unpredictable, you want to make him scared and confused about your own play, which will minimize the number of moves he will be willing to make against you, thereby making him more predictable and passive.