The Magic Forehead
There's a big difference between concentrating really hard on something and being perfectly aware of something. In America, we're used to working hard to concentrate on something, but I prefer not to work at concentrating when I'm playing. On the other hand, I want to be so perfectly focused that I know exactly what my body is doing at all times and am not distracted by things like: what other people think of my playing, whether I'm going to make that shift, etc.
I just made up a new exercise to get myself into that totally calm, focused, relaxed state. It worked so well it was scary, so I tried it on 6 of my students. It's a winner. One student played a passage, then followed my directions and did the exercise, played the passage again, and looked at me, dumbfounded: "why does that work?" "I don't know," I said, "but it's cool, isn't it?"
The purpose of The Magic Forehead is to practice focusing your mind in a relaxed way and to get used to forming a mental picture of what your body is doing, even when you're not looking at it with your eyes.
I'd suggest getting someone to read this out loud to you so you can do it with your eyes closed (or record yourself saying the steps and then play the recording).