Being able to hit a golf shot with a higher than normal trajectory allows you to get over obstacles such as bushes or trees, or hit an approach shot over a bunker to a severely elevated green. The shot is not complicated to execute.
Take your stance with the ball positioned more forward than normal. Two-time U.S. Open champion Curtis Strange says placing the ball about one ball-width farther forward is ideal. This has the effect of adding loft to the club, causing the ball to fly higher.
Take a normal swing, concentrating on staying down and hitting through the shot. Avoid the tendency to make an upward scooping swing to produce more height; it can have the opposite effect and cause less-than-solid contact with the ball.
Make sure you extend your arms through impact with your wrists firm; don't allow your left wrist to break down or cup inward. The instruction book "Master Strokes" says a golfer should have an image of his arms forming a letter "V" after impact, with the shaft of the club pointing right between his arms.