Here's some thoughts on composition.
Visual FlowAs the viewer looks at an image their eyes move around to view each part.
The eyes will follow elements like edges, lines, shapes, etc, across forms in the drawing, even if they are separate objects.
Flow encompasses the image as a whole.

The flow of the right side is good.
The hair and the jaw lead us to the firefly.
But on the left there is nothing leading us back into the image.
While this isn't a bad thing the eye has nothing to do once we move out across the eyeline past the firefly.
Then we come directly back to the rest of the image.

We can catch the viewers eye with forms and lead them back into the image.
This keeps the eye flowing around the image easily.
EyelineBecause these are characters in our mind we percieve that they are "looking" at each other.
An eye is a powerful symbol.
We look where the character is looking along a line to see what they are looking at.

The eyeline here is flat, Completely horizontal.
Horizontal elements are stable, calm, and have little motion.

The eyeline here is diagonal.
Diagonal elements are unstable, exciting, and have a sense of motion.
MotionA static image doesn't move.
But we can still perceive it as moving.
Looking at an image we suppose that something happened before this, and something will happen after.
We can drop hints for the viewer that will amplify the sensation of motion.

1. The trail of the firefly shows us where he has been and we can predict where he is going. small accents emphasize turns.
2. The "dust" from the trail is drawn in a vertical progression which makes it appear to be falling.
3. The posture of the head and neck appears to be pulling back and tilting up.
4. The hair appears to be swaying as follow thru to the motion of the head.
Opposing ShapesShapes are similar to visual flow but deal more with individual objects and how they interact, rather than how the eye move across forms.

The rearing back version somewhat resembles the iconic head of a horse, like a chess piece.
The firefly's trail makes a similar shape overall.
While its not a blatant feature of the image it has some interesting properties.
Color GroupsThe eye connects areas where colors re-occur.
I like to think in groups of color, but the same is true of individual colors as well.




Try making the entire image and then focus on the details. Like rough background, rough shapes. Basic shading and lighting.
Yes this is good advice and common process.
Complete the image at a very rough level.
Try a bunch of quick versions of the same subject with different properties.

There's a lot more to composition than this.
Also there's plenty of reasons to do things completely opposite of what I've done here to achieve a desired result.
Use the basics and do creatives things.