Musically speaking, of course.

Another thing I've learned the hard way.

The assumption, of course, is that the teacher is a master at producing the sound you want to make.

So when the teacher says "do this" or "do it this way."
Just do it.
EVEN IF
it is NOT the way you would have chosen to do it
it is NOT the way you usually/always do it
it is NOT easy
it does NOT make sense at the moment

The assumption is very important. Don't go to a classical violinist to learn to play bluegrass fiddle.