When on the lesson tee and observing a new student who is not a raw beginner, I always analyze their fundamentals, but also watch where the bottom of their swing is. Research conducted by Bobby Clampett while working for CBS has proven that regardless of swing style that the bottom of a tour players swing is 4 inches past the ball and that for every inch a golfers swing bottom backs up their handicap goes up 4 to 5 points. That is a pretty significant finding in my opinion.
Improving this one aspect of your swing can truly help you enjoy this great and challenging game. All you do is simply place a tee in the ground where the ball would be and make swings attempting to clip the grass or make a divot and see where your swing bottom is. If it is in front of the tee consistently after at least 5 swings in a row this important swing dynamic is better than most.
Remember a tour players swing bottom is 4 inches in front of the ball. Strive for that and you have one very important component of the golf swing heading in the right direction. Practice when you have time and enjoy the challenge of this great game.