Reality vs. Memory

Some "girl art" for you all. The color piece is one I did entirely from my imagination in photoshop. The other is a charcoal drawing I sketched from life. There are things I like about both of them. Obviously, the charcoal piece has a lot more life and character to it. You get the feeling she is pensive or worried. The color piece seems a little dead in the face. The thing I want to learn is how to give a drawing done from imagination the same character and emotion that you would get if you had a model in front of you.