[tylercubell]

The first strategy I completely agree with. Growth happens outside of your comfort zone.

The second and third strategies I don't completely relate to. If it works for you, great.

The fourth I would somewhat disagree with. You need to know where you're going before you start playing but "moving towards a perfect mental image" is just silly. Is this piano player trying to be a robot? There are countless ways to play certain pieces and a lot of the time it depends how you're feeling that day. Play like a human being. This quote by Beethoven is apt, "To play a wrong note is insignificant; to play without passion is inexcusable." I would say the most important thing is to play with passion and to try to stay true to the spirit of the piece you're playing.

Source: my personal opinions after playing classical piano for 14 years.