It is obvious that you can hit a good shot even if you follow through awkwardly, for nothing you do after the ball leaves the club head is going to influence where the ball goes. But a sound follow-through is still a vital element in a golf swing because it helps insure that everything that went before was done properly. What is a good follow-through? In general, there are three important elements to look for: 1) how the hands finish, 2) how the right shoulder finishes and 3) the position of the head.
Ideally, the hands should finish high. This indicates that you have brought them straight through the impact area and out toward the target. If the hands finish past and below the left shoulder it usually means the swing has been too flat or the wrists have rolled over excessively at impact. At the same time, the right shoulder should stay down and underneath the left. This indicates that you have hit straight through the ball with all your power, and not pulled the face of the club across it. Finally, the head should be kept down but slightly tilted, to the point where you watch the flight of the ball almost entirely out of the corner of your left eye. This means you have maintained a steady position throughout the swing and stayed down to the shot.