I can only tell you what has helped with me, not a teacher, devoted to this site. When I swing too inside out, which is my tendency, In order to keep from flipping, my left wrist and arm get higher, causing a thin shot to right. If I swiveled, I hit a huge hook. It is a plane issue. I need a tumble, so that I do not get underplane. Then I can swivel and hit the ball with a slight draw. Taking my right thumb off has helped, so has NHA and to an extent NSA 2. In my swing, when I come in too far under or in to out, clubface opens too much. Twistaway helps a lot. Bottom line, I need to start down to the ball on plane for the club path to go left enough and not too far out to right field. I have a strong left arm, I pull a lot from the top, swing to right and left wrist essentially blocks the club from releasing. At impact I try to get the shaft up the left arm. It feels like flipping, but without the right thumb on the shaft, as long as my right shoulder drives, I hit the ball great. I cannot drive the right shoulder when I swing too in to out. Watch Kenny Perry, that is how I try to keep from swinging too in to out.