I think that one under-utilized strategy is stop and go betting. What this refers to is if you have a short stack in a tournament and it is raised to you simply call instead of going all in. Then plan on going all in whatever the flop is. This works especially well if you are the first to act after the flop, i.e. one of the blinds.
The reason that I advocate using this strategy at times is that you may be able to win a few extra hands by inducing a fold where you would have otherwise been called. For instance, if it is raised to you preflop, and you go all in for less than a pot sized bet, you are almost sure to be called. This ensures that all five cards will come out giving your opponent the best chance to beat you. If you are the short stack then surviving is key, therefore you want to maximize your chances of getting your opponent to lay down a hand and winning the pot uncontested.
If your opponent doesn’t have a pocket pair, there is an approximately 60% chance that the flop will miss him. So if you fire a bet at him, even a small bet, with all your remaining chips there is a good chance that he will fold and not try to catch the two more cards that might kill you. And if he does call you would be no worse off than if you went all in preflop, i.e. you’re seeing all five cards and whomever has the best hand at the end will take it down.
The basic point is that you should always be looking for more ways to win than to just shove your chips in the center and let the cards fall where they will. Unless you have an excellent hand it is almost always best to win without a showdown, because even AK has a 33% chance of getting knocked off by a lousy 7-2.