Feedback

Improvement occurs through feedback. Feedback should therefore be constructive, not an instrument for exercising power. You have the right to receive feedback on your work, so ask for plenty in order to prevent any single comment from holding too much weight.

How to receive feedback:

Take a positive attitude to enhancing your skills
Listen to everything that is said
Pay attention to the content, not the feelings that it awakens
Avoid trying to explain yourself
Ensure that you have understood correctly (source: Sari Lindblom-Ylänne)

Only give yourself feedback on a performance after it is over. Learn to focus on your performance so that you don't start congratulating yourself or worrying about a mistake in the middle of a piece you will only make mistakes in the next bars.