To improve, change.

What did a master voice teacher like John Lester say or do with voice students who came through the studio door wanting to improve their singing?  John Lester had a peculiar ability to identify remedies to technical singing problems no matter what they were. Very basically, however, he would simply inform students that, if they were going to improve, they had to change what they were doing. It seems so basic, but without that starting point, little improvement was possible.