-Firstly there is imagination, then there is life drawing.
We need several tools to create acceptable images. Images that can capture our imagination or life itself.
A good hand, good tools, and a good eye.
How do we develop these things, aside from a miracle?
Practice, practice practice.
The foundation is line. No matter what kind of drawing your doing, interesting line creates interesting drawing. Even brush work is based on your feel of line.
Doodling is the foundation of interesting drawing. We all doodle as children. We let our imaginations run wild, and create what flows naturally. All great drawing techniques came from experimentation, otherwise known as doodling. Have you ever been painting, or doodling something, and on your test paper that you use to mix colors or prepare your brush, drawn something better than the actual illustration you were working on? This is how much inspiration comes to be. New techniques spring from nothing. They appear on our paper as an accident and evolve into our next great achievement. Sketching is fundamental to artwork. Some artists prefer to stay sketching their whole lives. It is their artwork that continually evolves. If we become always too tight and finished with our line work, we get stuck in a "style." Sometimes that pays off for a commercial artist whose artwork is adored. Personally, I prefer to experiment to the point where all types of drawing becomes accessible.
It is important to have vision. You may not be where you want to be. Granted, I'm not where I want to be artistically, but we must be content. We must be at peace with where we are, but have a vision. Discontent and frustration shows in art work. Sometimes vision will appear spontaneously while other times it comes with meditation. Without it our artwork becomes stale and regurgitated. We must have direction, even if we can only see it through a key hole in our souls.
How do we practice line work? We just practice drawing, that's the fastest way to develop good line. Often times the artist will neglect life drawing, but this is the best way to develop good line. When we draw while looking at life, our line becomes more spontaneous and life like. This can then carry over into drawing from the imagination. Our figures and faces drawn from our head will begin to have a life like presence. Make no mistake, even the most simple cartoon work can benefit from life drawing and having a knowledge of the real world.
Once we've moved on from line work, we can explore such areas as basic perspective and shading. These two areas of drawing go hand in hand, as good shading, good manipulation of light and dark will often create depth, which is basic perspective. Shading can be applied to almost anything, even type-fonts to engage the viewer further in the art work. Even art that we often think has no shading often does. If you look at japanese animation, which is often colored in flat tones, the face will be a lighter tone ever so slightly than the arm or neck, drawing the viewers eye.
Now that we've touched on the manipulation of the viewers attention, we can move onto composition. In my mind, composition is the second greatest principle of good drawing. We use composition to capture the viewer's attention. Light and dark, thick and thin line, even color theory can all be used to create attractive composition. Things like dividing your paper up into thirds, a tool used in paintings from the romantic era can be used to capture the viewers eye. I wont explain it here, but i use it as one of the many examples of drawing techniques created to create great composition. Our line work or our placement of objects can draw the viewers eye. For example, an artist can use a branch in the foreground to attract the viewer to the main subject in different ways. It can be positioned so that the viewer is led to the subject or it can be shaded in such a way to lead the viewer, or both. Every object in an illustration can be used to the artists advantage to create mood, draw their eye to the focal point, or be used reach whatever end the artist is trying to reach. If our composition is weak, our drawing is weak.
-Essentially, composition is the manipulation of the objects in our artwork to reach a desired effect.
We must have a good foundational knowledge to create good drawing. What i mean by that is that we must have a good knowledge of anatomy and perspective in order to create good drawing. Every object in a drawing will fall under some kind of perspective or lack thereof. Getting a good book on perspective is fundamental, as well as good tools to learn anatomy. A life drawing class in recommended in order to create convincing figures. Figures are essential to create life in our drawings. Emotional responses are often created from some sort of emotion being conveyed in the figure; a hand touching the face in a certain way, hips tilted a certain way and so on. A grasp of body language is essential. Drawing from life in invaluable when it comes to subjects like this.
Then there is color theory. Basic principles of color must be learned, like how colors compliment each other, and the use of primary colors to get the reader's attention. For example, Superman is colored entirely with primary colors, red, yellow, and blue. Stark colors can create great focal areas, while subtle coloring can convey an amazing sense of mood. Great color work is essential for conveying mood. Granted, much can be conveyed in black in white, to the point where the viewer does not even desire color, but color must be one of the tools in the artist's arsenal to be complete.
Of course we must have a knowledge of what artwork is out there. Take the time to appreciate other peoples artwork, in a museum, in a comic book, on the web, or whatever. It is an enormous waste of time to think that our ideal style can be achieved by shutting ourselves out from the world of art. Although there is room for a certain amount of artistic isolation to create uniqueness.
That is the key, for personal success and satisfaction as an artist, we must have vision, and we must be unique.