I have struggled with the same problem for probably the last year. I have tried changing or altering everything under the sun with no consistent results. About three weeks ago I decided enough was enough and that I was going to fix this. I went back to basics and made a list of things to check. It was to my surprise that my problem was the second thing on my list right below grip. Posture. I think correct posture can cure many of the problems posted on this board. It is hard to make a good swing when you are not in the right position to begin with.
My posture problem was a hunched over back and poor butt position. In Hogan's five fundamentals he explains that you should feel as if you are lowering yourself onto a stool and that you should feel your weight in your butt and the back of your thighs. I was only bending over from the waist and slumping over with my back. Even though this lowering motion moves your mid section back a few inches it is enough to make a difference. When I had bad posture my hands got stuck behind my body, especially with the woods and long
irons. All I could do was push it to the right or whip my hands around and hook it. This also explained why I would start out great some rounds and lose it halfway through. As that wonderful Florida summer sun wore me down my posture got sloppier and sloppier. I also found that this posture is what led me to sh**k my chips on occassion. My hands had no room to go forward so they went out towards the ball and hello hosel rocket.
So, for me anyway, I just have to concentrate on that posture and things seem to go well. It is so easy for me to get sloppy being a big guy (6'4"). This fix may seem simplistic to many of you but I have found fundamentals to be so the most important thing in a golf game. Reading gold digest, golf magazine and all these web-boards can sometimes be a curse as you start to get to technical and screw yourself up even more. Just take a look at the different suggestions on this topic alone...pull down with the left side, standing to close, a different takeaway, headcover in the armpit, let the club drop from the top. It could take a half dozen range sessions to work through those suggestions. (Respect to all, I am not bashing you suggestions. I am not saying I am right, I know we all just post what has worked for us. I am just using these as examples) A pro at a course I worked at in college said the golf magazines were his best friend since so many people screwed up their swings trying to follow the "hints and tips".
My advice for everyone struggling is go back to basics and try to learn to be a feel player, not a technical one. If you have more than one swing thought on each swing, you are getting to technical. The only thing I think of on every swing is swing easy since I try to kill it sometimes.
Build a solid grip, but grip the club lightly
Good posture
swing easy
trust your mechanics
Get a few lessons with a good pro before buying that cure-all training aid or dvd. If you are going to buy a book or dvd, buy one that focuses on the fundamentals, especially grip, posture and address.