Hi Mike: A key to acheiving professional sounding chords is to strive for 'smooth' as possible voice leading, meaning not to move your hand (and fingers) unneccesarily when transitioning to succesive chords, but to find appropriate chord voicings (chord inversions) which minimize jumping around the keyboard. If at all possible, keep the finger (individual chord voice) on the same note(s) or move them only a 1/2 or whole step, during a chord change.

I recommend practing (memorizing) all the basic 'left hand' chord types (and in every key) in all inversions, and then practicing & memorizing them (with smooth voice leading) in these most commonly played chord progressions:

I - VI - IV - V - I

I - VI - II - V - I

Ok, I guess that should keep you busy . I believe with your teacher's guidance, you're headed in the right direction to succesful left hand chord playing. Good luck.

Scott