Aggression is good in Hold’em
Once you get the cards you’re looking for, play them aggressively! If you have the best hand, bet it and force the weak players out. To many new players make the mistake of slow-playing those aces, allowing someone to stay in cheap, and that someone ends up drawing out to a better hand. Make them pay to play.
The only exception to this might be when you have the “nut” hand, (the best possible hand), and you are attempting to build the pot by letting others limp along, getting a few good cards that will entice them to stay and call you on the last couple of expensive “streets.” But do not overestimate the strength of your hand and allow people to limp in and beat you on the river.
Look at your “call”, “raise” and “fold” percentage. “Fold” should rank #1, followed by “raise” and finally “call”. If you’re pretty sure you have the best hand currently, raise it. If you think you’re beat, fold it. The only time you should be calling or checking is when you’re drawing to a flush or straight, or you’re calling what you think might be a bluff.