I fly by getting my brain in the airplane. It's the only way to go, the other things are just ways to help you get to where you are flying brain-in. Personally, I learned with the "stick to the low wing" method, and I tend to prefer that to the over-the-sholder method when teaching, and as long as you eventually start thinking as if you are in the plane, it doesn't matter. Guys who still look over their sholder after flying a few years are the ones I watch out for

One advantage to getting the brain in the plane is that you don't have to see it all the time, and you loose orientation a lot less. I've had moments where I couldn't tell which way a plane was going visually, but since I KNOW what the plane is doing, and nothing strange happened, I know what the orientation is, even if my eyes can't fill in all the details, the brain knows the rest.

it also helps dramaticaly when things go wrong and you have to go for a save. People who have been flying long enough start to fly by reflex and "feel" and that only comes with getting the brain in the aircraft, even if they don't think of it that way. It's that instictive knowledge of what way is left and right and up and down, no matter what the plane is doing.