Teachers and students can learn to give more useful constructive criticism by practicing on musical offerings that are personally relevant and interesting. The goal of each inquiry is to identify a problem area and improve it.
This Inquiry into Music: Course Home-style module provides suggestions for a number of ways to practice giving constructive criticism, including:
Constructive criticism is fundamentally different from the type of professional criticism that has the purpose of letting people know whether or not they would enjoy a particular concert, movie, or book. The purpose of constructive criticism is to help someone improve. (See Constructive Criticism for a thorough discussion of the subject.) So for each of these exercises, the sign that you did a good job will be noticeable improvement.