Since I've started playing No Limit Texas Holdem Poker on a fairly regular basis, I have to say that one of the most important lessons I've learned is that you should never let your opponent see a card for free. Strangely enough a lot of the people I play against both online and off seem to ignore this all important lesson and I don't understand why.

The most common play I see, especially online is people limping in* before the flop. This is a horrible idea. When you limp in, you are representing a weak hand, you are encourage a lot of action against the pot, and worst of all you are potentially allowing the Big Blind to see a flop for free. This can have disastrous consequences. Take, for example, a hand I played in a recent online game.

I am in the BIG BLIND.
I am dealt 7c 2s (considered the worst opening hand in the game).
3 players limp in, everyone else folds.
I CHECK to see the FLOP for free.
FLOP comes 7s 7h 2h, (giving me a full house).
I bet the minimum, hoping to eliminate high cards and entice someone who is on a flush draw.
1 opponent folds, 2 opponents call.
TURN comes 4h.
I CHECK, hoping someone hit their flush.
1 opponent bets the pot.
1 opponent calls him.
I RAISE ALL IN.
1 opponent folds.
1 opponent calls.
I turn over my full house.
He turns over Ah 10h (an ace-high flush).
River comes Ks.
I WIN AN ENORMOUS POT.

You see, if anyone would've raised even the bare minimum amount, I would've thrown folded my hand in a hurry. Instead, I was able to see the flop for free (since I already paid the Big Blind). I urge you if you are playing this game, don't limp in. Countless pros will tell you the same thing. Chris Ferguson even lists it as his #1 tip and talks about this as being "The Worst Play In Poker".

Of course, limping in is not the only way to let an opponent see a card for free. I also see a lot of people checking on the flop. I can not get over how many online hands I watch where everyone checks on the flop. I find that this too is a ridiculous play. Every time a new card is placed on the board, it has the potential to help your opponent's hand and hurt your hand. I say, make them pay to see the next card. Now, don't get me wrong, I'm not suggesting you make huge raises on every flop. However; a small bet, regardless of what kind of hand you have, will usually eliminate weaker hands from play and give you valuable information about those opponents who do not fold.

When I am in early position and I catch a dangerous flop (something with overcards or flush, or straight potential) I tend to make a small bet at the pot. If someone simply calls, chances are s/he is on a draw of some sort. If the next card misses I can bet more aggressively and capture the pot. If someone raises over top of me, I know they probably have a strong hand and I can let weaker cards go.

When I am in late position and everyone checks to me, I can almost always make a strong bet and capture the pot. Of course, if the person checking is someone who I've seen slow play his top hands I might be a bit more cautious with the size of my bet.

Please understand, I'm not saying that I will never check. In fact, there are three scenarios where I usually check.

1. I am in the Big Blind and I can see the flop for free with a weak hand.
2. I have total junk, I'm convinced my opponents have me beat and the pot odds suck.
3. I have an extremely strong hand (usually the nuts) and I am sure that someone will bet in to me or that I will still have the best hand even after my opponent sees a free card.

Remember, despite what I've said here, it's always a good idea to vary your game so that you do not become predictable, however; I believe I've presented you with some good guidelines to play with most of the time.