QUOTE(Pixie*Porsche @ Dec 11 2011, 12:44 PM)

In my opinion the worse thing you can do is think of the staves and hands as entirely separate. I was convinced for a very long time that I couldn't read bass clef effectively and had a "slow" Left hand, not the case at all I just didn't practise effectively.
There you go, that's what I get for being a non-pianist
However, I have to agree, and perhaps my post was poorly explained. My point wasn't to try to get so that you can think of both hands as being independent, but rather to get to the point where you are more comfortable with your left hand. Many people go through life without realising they have two hands, and when they come to do something that requires the use of both, they find that their long-neglected left hand is harder to coordinate. Doing some of the things I suggested will get you more in touch with your left hand. It's worked for me for martial arts, guitar and Taiko drumming.
But Pixie*Porsche speaks the truth. You need your hands, and the staves to work together, not independently. That's true in drumming and guitar (and in Martial arts to an extent), so I'm not surprised to hear it said about piano!