The quality of your lighting is driven by the answers to two simple questions:
1. Where do you want the shadows to fall?
This determines the placement of your key.
2. How much do you want to see into the shadows?
This determines the amount of fill you use.
Everything else – composition, color, movement, grading and other post-production manipulation – follows in kind.
And, as always, all of it is governed by the manner in which you apply your taste!