I'm left handed. I have focused on keeping my right arm straight but not stiff. I don't have the flexibility that many players like Erik have. I've seen photos of Ernie Els where his left arm is completely straight and completely vertical (perpendicular) to the ground. This is physically impossible for me. I've had some shoulder injuries from MMA and college football.
After GMS program in Colorado I was doing the best ball striking I've ever done. My biggest flaw was a very strong grip and coming WAY inside. So bad that I sometimes almost hit my back foot coming down and through. Inside, closed face....shank. When my timing and crazy manipulations were working, I could play some good golf. But when it was off, I'd shoot mid to high 80's.
I really have to ingrain the proper backswing and downswing which I've been working on diligently. I didn't get the feedback I was hoping for after posting my swing but no complaints. Erik and Mike are awesome and I've combed thru enough threads to learn so much from them. Erik and Dave's book LSW
was an awesome read and has really helped me with my plan on the course.
Sorry for the tangential babbling. I feel Herman Williams has excellent info on his videos. Nothing beats in person lessons for me but it's the next best thing. I love this crazy game so much. Hell, if I hadn't buried myself in student loans...I'd find a way to make a career in golf!
From what I've read and the videos I've watched including: Herman, Hank Haney, Mark Crossfield, Shawn Clement and Erik....I'd probably most prefer Erik with Herman Williams a strong second. That's just me.
I'd say the two main thoughts that seem to keep my ball striking solid are steady head and weight forward. Keeping these thoughts with a straight but not stiff right arm really keep me in a good swing.