Learn to Recognize Certain Winning Opportunities
If you want to play chess to win then you should learn to spot certain weaknesses in your opponent's play and/or be able to take advantage of certain opportunities that come your way during the course of game. Intermediate players will have some sort of an idea of what such opportunities are since they have gained some experience with the game.
The opportunities to take advantage of don't necessarily mean that you'll win the game right there and then. Sometimes they help you gain material, take considerably better positions on the board, or come right into checkmate if the opportunity allows. Either way, the secret is to be able to spot such events that are beneficial to you. At times, both you and your opponent may play your own individual moves solidly and have everything pretty even until one of you makes a bad move and breaks the balance.
That is essentially what we're looking to take advantage of. When one learns to recognize such decision-making errors made by your opponent then one may capitalize on such events. There are basically four things you would have to consider as important events in a game that brings you the edge over your opponent.
These four items of interest are when your opponent's King is exposed to any form of attack, when your opponent develops chess pieces poorly, when the opposing Queen is in danger or otherwise out of the game, or your opponent was taken in surprise. These are basically four landmarks on the game that gives you insight towards defeating your opponent. These also aid you finish the game and win as quick as you can and save you a lot of trouble.
Beginners and intermediate players sometimes commit the mistake of having the King exposed to enemy fire. This opportunity could come in the form or time when your opponent fails to castle, or it maybe your opponent left the King without any piece to guard it or the other chess pieces are too far away to help, or, as a completely novice mistake, the King came out to hunt for the enemy.
If you've played several games now, you should be able to recognize that some squares on your board just don't help your other chess men make use of their true and complete potential. You should also look into your opponent's Pawn structure and see if there are any holes in that line of defense. Another weakness is when the enemy Queen is in a tight spot or is out of play. This means you have a better chance of winning with the material advantage you have on the board.
All these set you up to take your opponent by surprise or to overwhelm your opponent's forces. The player who recognizes such opportunities will gain the advantage and will play chess to win.