The Basics 
This site endorses the practice of -Yes, no, maybe...
Taking time to mull over decisions shows weakness in your play, especially if you were to call. Really, if you have to ‘think’ about anything, you already have your answer, and the answer most likely is to fold. Properly you should know when calling with your starting hand exactly which cards will help you so that if they do not turn, you can easily fold or make a decision to call for one bet without hesitation.
By simply looking at the cards in your hand, as soon as the next card is dealt out you should already know if the card was no help, if it provided you with possibilities for outs, or made your hand. You shouldn’t have to necessarily look across the board if you are playing tight combinations. You will know if your cards have hit or not regardless of what other cards are playing in another player’s hand.
Definitely think about what you are doing, and at the same time do not let other players know it. Taking obvious periods of time to think about checking, calling or betting opens the door for your opponents to see weakness in your hand. At all times you must either represent that your hand is strong with multiple outs, or that you will fold.
Alternatively taking a ‘think’ period or hesitating to call a bet or raise can be used as a strategy to hide strong hands and keep your opponent betting or calling into your made hand. This should be done under two conditions when you know that you know you have the winning hand; on later streets when the bets have graduated to the table maximum and a scare card comes up on your opponent’s hand so he has an idea of exactly why you need to take a moment to think. If your opponents are accustomed to your quick responses and all of a sudden you take a moment to think, it’s can be an obvious tell that you are slow playing a very strong hand.
The second condition is if you have an early-made hand such as rolled up trips, aces- or kings-up on fourth street, or a fifth street hidden full house. With early-made hands, the rhythm of your betting should remain consistent at a medium or slow pace if you use hesitation strategy. When using hesitation strategy, bets and calls coming from you should not go at the speed of zero-to-sixty in split seconds if you want to get the most out of having your opponents continue to bet into the pot. Keep the rhythm and the pace even and consistently a tad bit slower than your norm from the time the bring-in is made at the table. This will give them the idea that you are on some sort of a draw or that you are really concentrating on their hand looking scary.
When the opportunity calls and a player has shown weakness in their hand by thinking and you know that you have the better hand with live outs to make it even better, raise them if your position allows. You might even make your calls more quickly than normal to scare them off of the hand representing that your hand is dominant.
