Let's talk about posture and balance for your two different swings, two-plane versus one-plane, because the fundamentals are totally different.
Stance in a One-Plane vs.Two-Plane Swing
In a one-plane swing you are going to be bent over quite a bit more than in your two-plane swing. It does not matter which one of them you use, you want to be balanced on the balls of your feet. I do not play any sport from my heels where I can tap my toes, not that I can remember. I do not play any sports where I am trying to balance myself out on my toes. I want to be on the balls of my feet.
So even if I am standing up for a two-plane swing, I would be a little taller and in a one-plane swing I am going to bend over a little bit more. Now when you bend over you are basically counter-balancing your body. As your head goes forward your behind goes back, that keeps you balanced on your feet. You have even seen baseball players, they train little leaguers to bend at the knees and actually put the glove on the ground. Now that is counter-balanced.
Counter-Balance Your Body
I am still on the balls of my feet but I am really bent over. A lot of one-planers, when we are teaching them to get their arms around them more, they feel like they are bent over 90 degrees. Of course they are not, they are only bent over more than in the two-plane swing, but it feels enormous. In all parts of the golf swing you are counter-balanced.
Both at address I am counter-balanced, at the top of my swing I am counter-balanced and even as I go through to my finish position, when you see this position on TV all the time, and the head is out over the ball a little bit more, the hips are pushed out a little bit the other way, so I have them counter-balanced with my body. So get yourself in the posture to match your swing, get your body counter-balanced throughout your golf swing and you will get better results.