Stay within your table profile.  If you are betting and raising every hand, keep betting and raising!  Nothing looks more suspicious than a player that has been betting and raising who checks on the flop for the first time.  I can't tell you how often I've seen Player A raise the BB, continuation bet and take it down.  Than, out of nowhere on the AKJ board, he checks  and wonders why he didn't get paid off with his QT.  If you're always betting and raising, no one is really going to believe you.  But that doesn't mean they're going to be able to play back at you without a hand either.  Most people just aren't that good, to be honest.

"Make your opponents believe what you want them to believe"

As an observor, one can often tell who will win a certain, based on previous actions and bet speed and size.  Even though you can't tell what cards they hold, you can make educated guesses on who will be the winner of the hand.

"Don't become so attached to a SNG that it hurts when you lose."

I love being able to lose a SNG and feel like I played as well as I could.  Lots of times, you WILL run into big hands.  You will try the Squeeze Play and run into AA.  You will try the Stop N' Go play and run into a set.  You're gunna get your button raise reraised from the BB.  It's all going to happen, every single thing you could imagine is going to happen if you play enough.  You'll realize that sometimes a pair of four's is going to win a huge pot, and sometimes you'll have to lay down KK on a King high flop.  Sometimes your turned set is drawing dead to quads.

Believe it or not, all of the above has happened.  I lead out my quad 3's on the 336 board and had action - all because I had been betting and raising...plus who expects you to lead out your quads?!  You're probably going to get more action out of that hand than by checking.  So rather than make a "I'm scared you'll fold" check, I made a normal continuation bet.   Or how about
when I had to fold my KK on the KJ9T 3-heart board.  A player was all in, and for some reason I made a dumb check on the flop. Then a 3rd heart hit the board that also straightend out the board and he went all in.  I folded, kicking myself when I would have rivered a boat to his flush.  Or when I called a 3500 bet on the river with J4o on the 248TK board.  Ended up taking a huge chunk off of him.  Or how about when my UTG raise with 66 was min-raised (huge hand tell).  The board came A82 and it went check-check. The 6 came on the turn for my set, but ended up folding on the river to a serious AA value bet.  He showed AA and I kept 320  chips in my stack. 

My point here isn't to boast about my accomplishments (in fact, I played the KK hand poorly!) it is to remind all the people who say "that guy just called an all in with bottom pair!"  Sometimes the situation, and the board texture allows you to make a wild call like that.  And sometimes you just know you are being set up with a monster, and you can release the monster of your own. 
It is easier to tell from the rail who has the winning hand before the hand is shown, but sometimes your hand just looks so juicy that you can't lay it down,  and end up paying your opponent off.  Don't!  Just because you flopped a set, doesn't mean someone can't river a flush on you. And if the action has indicated that he indeed caught his flush, why would you call his bet/raise on the river?  When do you ever see the caller of the bet winning the hand?  Hardly ever.  Don't be a river caller!

This brings me to my ultimate point.  I believe that you must totally leave your emotions at the door when you play poker. Poker is about making the most correct decisions you can.  The correct decision isn't always the statistically "right" one, but its the one that makes the most sense at that moment in time.  "I just raised with QQ and stole the blinds, so this next hand I should be given some credit.  I should raise with J4o here."  Or "I don't have enough chips to take this next set of blinds, so I'll have to push UTG next hand - Uh oh, 35o...I still have to go all in, hopefully no one calls or I get lucky."  Make the play that you believe is right.  You will surprised at how often you are.

-gidders