For my part, I think that finding the right instructor is the most difficult part. You need to find a Pro that will adapt to your style and morphology otherwise he will change you too much to really appreciate it.
I've tried many good Pros, but few of them were good for me.
Now I practice in a place called Golf ONE near Montreal where I can get good Pro Advices while practicing on Golf ONE Simulators, which analyze each swings and gives good feedbacks.
Within the last year, using this technology once a week, I passed from Mid 90s to High 70s while enjoying the game a lot more. I've learn how to control the ball and how to do beautiful Draws. Today, I can go for the PIN at 185 Yards.