Here are some tidbits from pages 84 - 172.
One could argue that a player is nothing more than the sum of his betting patterns.
And that those patterns are lying right there in front of you and online in their hand histories. The essence of a good trap is to make a play which looks routine for you. When players get suspicious, you can't trap them. So just make your usual bet, and see what happens.
An oversize raise is more likely to indicate a hand that doesn't want a call. Players with made hands are more likely to want you in the pot against them. This is somewhat true but in low money buy ins online people more than not are going to make a big raise or go all in after the flop with TPTK, a set, and their chased flushes. Possible flushes on the board are very good bluffing opportunities. Most people are scared of them. Players with made hands are more likely to want you in the pot with them.
Try and raise the amount you've seen people fold to in the past.If they're calling bets of 3x the BB try raising 4x or 5x the BB. Take notes on what the people in the blinds near you will fold to. This will be important when the blinds are big enough to steal later in a SNG.
Later in a SNG when down to just a few left and you are the short stack. You look down at 85 or 910 suited. AJ or KQ is only a 5-to-3 favorite. You should be much more inclined to risk and all in with 86 or 109 than A6 or K5 as you may be dominated by a bigger K or A.
Bluffing is a big weapon for the conservative player, because it's so unexpected. Players like us know their bluffs will almost never be called because of our table image, so we know when we do make a bluff it's usually a high percentage play.
You usually want to raise with your AK but sometimes against loose-aggressive (LAG) players it might be right to limp and make a big reraise preflop.
Players short stacked and in the SB who go all in usually have a pretty decent hand. If it was junk they have enough chips to survive another round or two to find something good. They usually have a pair or two high cards.
People online are much more likely than in a B&M to shove their chips in with nothing or just a low pair.
You make a big raise with QQ preflop and two other shorter stacks go all in. It's very possible they both have an Ace with hands like AJ, A10, A8, AK or one has something like AJ and the other has lets say 99. Your hand is probably going to win a great deal of the time, only 30% of the time an ace will show before the river if they have AJ and 99. If they both have an ace they usually won't catch one because there are only two left in the deck.
Beginners usually shove all their chips in when they hit their flush. Resist this temptation and just concentrate on how to extract the most money from your opponents.
When you want a caller don't bet more than half of anyone's stack. Losing more than half of your stack is a real psychological barrier and you don't want to push anyone across that barrier unless you know for sure they'll call it.
I'll have more tips from Harrington On Hold'em Volume One in a few days.