As TP suggested in an another thread, I'll take a stab at hitting some of the key points in SNG strategy.
To start with, STT SNGs are the most thoroughly mathmatically analyzed form of poker that exists (because most SNG decisions are pure math). ICM (independent chip model) is generally the most cited source of late game SNG analysis. While I'm not a pure ICM wonk, I intuitively understand the theory, which basically is all about making the proper late game moves that mathmatically increase your theoretical share of the prize pool.
Thus we begin with the idea that the key concept in SNG strategy is understanding $EV vs CEV. The other main concept is that of non-exploitable strategy. I'll hit a couple of points in this post and refer back to these ideas.
Concept 1: The Early Stages
Basically, all the best SNG players advise being the tightest nit on earth in the early (and even the middle) stages. I've read some that advise playing ONLY AA-QQ, AKs in the first two levels. I'm not that tight, but I'm getting closer. I saw one post on that other forum where a player had raised AJs 1st in from 2 off the button, 7-handed, 25/50 blinds and a stack of 1365, and while he was asking for post-flop advice, the best posters there all immediately said "fold preflop."
Lets analyze this going back to the concept of $EV vs CEV. ICM teaches that your stack size as a percentage of chips in play is exactly equal to your share of the prize pool. Thus, every time you put chips in the pot and subsequently fold, you lose money. Thus you only put money in with strong hands, and if it is AK and you miss you DO NOT c-bet EVER, unless your opponent is weak-tight post flop. This is extreme, but it is the type thinking the best SNG players use early. Wasting chips early is a sin.
non-exploitable strategy
This basically means that you should not adopt a strategy that is ostensibly +EV if an opponent can adopt a counter-strategy that turns yours from +EV to -EV. So, if you raise preflop with range x, but will fold subset y of that range to a reraise, a thinking opponent might exploit you by expanding his reraise range and making your strategy -EV.
The classic example of non-exploitable strategy, is bubble time, equal stacks od < 20 big blinds, 1st in from the small bling you shove any 2 cards. This straegy is clearly +EV because at roughly equivalent stack sizes, your single opponent will fold at least 87% of the time. Note that since he cannot make you fold, it is impossible for him to adopt a strategy that will make your shove of any 2 -EV. The tighter his range, the greater your fold equity, the looser his range, the greater your showdown equity. When you shove any 2, the best your opponent can do is reduce your EV to 0, by calling with any 2, and nobody will do that unless effective stacks are < 5 big blinds.
Multi-street strategy, wtf is that?
Once you get past the 25/50 level ('Stars structure) effective stack sizes will be such that, even if its not yet just a preflop game, play on the flop will likely commit your stack, so you can rarely float a flop and make a play on the turn. You may run into clueless folks who will underbet the flop and turn and let you chase a draw cheaply, but going back to $EV vs CEV, you are usually making a mistake to fall into that (though I'm guilty of this too often)
These are just a couple of basic points as an intro the SNG theory. I'll let you digest those (especially those of you playing these alien games) and make some replies. I'll try to answer them as best I can. bear in mind, I am by no means a world-class SNG player, but I have read posts from the best and tried to learn from them.