Hey Lucifer!
I believe you should look at drawing expressions the same way you look at drawing a figure. What I mean is, the same way you start with the basic lines of action (which can be only one, or more if you draw the lines between the hips and shoulders, or even the arms and legs) you should look for gesture lines in an expression. This can be a smile, maybe the way the eyebrows raise, if the nose is tilted, etc.
The same way a body has a structure, so does a face; you can start with a circle or a square, then you draw a line that defines the middle of the face, then the line between the eyes, the line that defines the eyebrows, the smile, and so on. (This as an example, of course)
After that, it's up to the shape of the face, the same way you would look to draw the shape of an arm or a torso if you were drawing a figure. You can look for cheekbones, the muscles above the eyebrows, the eyebrows themselves, or the eyes and the mouth, etc etc
In short, most of the time drawing is all about going from a basic structure that defines the action, to the details. It goes from the big picture, to the small picture.
Keep it up!
Noodle
