Posture!

One aspect that is often overlooked is how to sit at the piano (see the image). Very often students do not sit properly, and even if they are "set-up" correctly, they would slouch or crisscross their feet, compromising their posture, which is very important because it affects the sound and the technique. For young students who cannot reach the floor, it is important for provide a foot stool, or even better, a pedal extender, so that their feet are not dangling at the piano. Part of the energy from playing the piano comes from the feet!