The High Shot
One of the hardest things for many amateur players to do is to hit the ball high into the air. One reason is the contrary nature of golf - if you try to hit up on a ball, you'll usually top it. So do yourself a favor and make no changes in your swing. Just make two minor adjustments in your stance. First, play the ball slightly forward of its normal position. If you usually position it off your left instep, move it about a ball-width forward, off your left instep. Assuming that your normal ball position allows you to hit the ball at the bottom of your downswing, the forward position will ensure that you'll catch it at the beginning of your upswing.
Second, redistribute your weight at address, so that you feel a bit more weight on your right side. This will shift your center of gravity - and your swing center - behind the ball a bit, which is where it needs to be at impact if you want to achieve a high trajectory.
Then just make a normal swing, the goal of which should be to finish with your hands high. Don't feel as if you have to chase after the ball because it's forward in your stance, and above all, don't try to hit up on the ball. With the changes you've made at address, you'll do that naturally.