In order to get height on your golf shot, you need to understand the physics of the golf swing. For example, when hitting with a mid-level iron such as a 6 or 7 iron, know that if you swing down on the ball it will fly high. If you want to hit high with your driver you need to tee it up sufficiently high. You also need to build a repeatable swing.
Tee the ball high when you hit with your driver. At least half of the ball should be higher than the top of your driver.
Play the ball off the inside of your left heel when teeing off. If you are hitting off the turf, play the ball abut 1 1/2 ball lengths closer to your front foot than you typically would.
Swing down on the ball with your irons. Let the loft of the clubs do their work. If you hit the ball at the bottom of the downswing, the physics of the swing will loft the ball.
Loosen your grip to allow the club to release fully at impact. Hold the club just firmly enough that it doesn't slip out of your hands. You want to ensure you have no tension in your forearms or shoulders, and an overly firm grip will tighten those muscles.