Mix Up Your Game
The number one enemy of a poker player is predictability. If opponents can put you solidly on a pattern of betting relative to the strength of your hand, you are doomed. This is why it is so crucial to mix up your game when you play Texas holdem.
What it Means to Mix Up Your Game
Generally, what mixing up your game means is shifting gears. That is to say, if you've been playing tight for awhile and have developed a conservative image, mixing up your game might be to start throwing in a few bluffs or loose calls. Conversely, if you've been a maniac, bullying people left and right, slowing down and playing only premium hands can pay great dividends, especially if you've just been caught bluffing a few times.
How to Mix Up Your Game
If you're not accustomed to playing a way differently from the way you normally do, it may take some getting used to. A good idea is to wait until a situation where you've had success with your given style. This way if shifting gears is not successful, you should still be ahead. The best time to switch up your game is immediately after your playing style becomes obvious. For example if you just got caught running a huge bluff in a big pot, it's a great time to hunker down and wait for a monster. If someone has just remarked after you bet and dragged a pot about how you only put in chips with the nuts, it's your cue to start bluffing and playing unusual hands.
Notes on Mixing Up Your Game
You shouldn't necessarily take mixing up your game to extremes. If you've been playing tight, you don't have to recklessly splash every pot with chips to take advantage of your image. A few well timed bluffs or stabs at pots that no one seems to be interested in will be fine. If you're a maniac, you don't have to take a time-out from the game to switch gears, just play the best hands in early position and strong hands in late position, then bet your hand when you hit.