Have you ever heard of the golden section?
...yeah, all this really means is don't put stuff smack dab in the middle of the page.
In nature, there is a natural balance that is commonly reoccurring, in shells, in rocks, in the human body. If you can use this balance in composition, it will appeal much more to the human eye. While rules in art are meant to be broken, getting a handle of basic layout concepts will definitely help your art-- it's better to break rules knowing about them, than break rules while simply being ignorant.
Let's take a look at some basic examples of composition, good and bad. At first, we'll use a really easy to understand example, from one of my favorite themes: Japanese Rock Garden Layout
The most fundamental layout consists of 3 stones, because the concept of "thirds" and the triangle are fundamental to the Golden sect. Even Stone layouts with 5 or more rocks are based on the basis of the triangle. So, using 3 rocks to make a stone garden, let's look at some examples of composition.
First, what not to do:
Now, looking at the above example, it's probably pretty obvious why this is bad. All the rocks are the same size, making for no visual interest. They are also straight up and down, and make the picture look very flat. To make matters worse, the horizon line is also completely flat at the base of the stones, not really giving any interesting reference or sense of space. Basically, it looks like a preschooler drew this. Actually, that might be an insult to preschoolers... A preschooler would at least draw a sun in the corner.
This example is also pretty awful. The most painfully bad mistake is the horizon line drawn directly through the middle of the piece. This again makes the image very flat, with no sense of depth or space. The large, round "main" rock placed directly in the middle of the composition is also painful on the eyes. The two "support" rocks are basically doing no support, and their even uniformity makes the piece very boring. The only saving grace of this piece is the triangle made by the 3 rocks, but it does basically nothing to help the case.
In order to improve on this, we will want to integrate the golden ratio. The easiest and most basic way to do this is just to divide the space into thirds and pay attention to the "key points."
The golden sect is roughly based on thirds, 1/3 or 2/3. By dividing the space into vertical and horizontal thirds, and finding the points where the lines intersect, you can easily find the points on the canvas that are key to the golden sect, and are naturally the place the human eye "wants" to look at. By drawing the illustration to work around these points, and bring important points of the composition to said points, you can make a piece with much more visual interest for the viewer.
Here's an example of a "good" rock layout:
This layout has a lot more visual interest, builds a sense of space, and has a good "balance."
The first thing one will look at naturally, is the point of the "main stone", which is not only a dramatic point because of the size of the stone, but also because of its intersection with the upper right "key point." Furthermore, the stone is positioned at an angel, is jagged point is visually interesting, and naturally suggests a point of a triangle.
The other two "support" stones are also doing a lot of great work for the overall composition. Their positions reinforce the triangle suggested by the main stone. Their relation to each other also suggests several "minor" triangles built into the piece.
Another thing one will notice is that each stone sits on a different level of the page, and that each has a slightly different angle. This "chaos within nature," called "wabi-sabi" in Japanese (and closely related to the Golden sect), makes the piece much more aesthetically appealing.
Finally, the horizon line, while not being directly on a "third" line (which would actually look "overdone"), is "just off" the third line, re-inforcing the sense of natural slight deviation from perfection, while still paying respect to the golden ration. This horizon line does a lot to connect the stones, giving them a "context" or "space," and gives the whole piece a sense of space. You feel "depth" even if there's no shading in the piece whatsoever!
Looking up at this good example, than back at the bad ones, even though they are all 700 x 700 pixel drawings, the last one "feels" a lot bigger.
Can you see the lines?
Now, how does this apply to drawing Pokemon? Well, even in illustrating singular Pokemon, your piece will take on much greater vividness if you can use these points to create a sense of movement.
First, look at bad pikachu:
Now, let's look at better pikachu:
By drawing important parts of the Pokemon, like face, eyes, claws, tail, or wings, you can put emphasis on different parts of the Pokemon and create a sense of motion or vividness. The Pokemon will feel more "natural."
As a last example:
Now you know, it's not just the shading and coloring that makes your eyes naturally draw to my avatar's eyes or claws. Even before the coloring happens, the drawing is laid out to naturally draw the eye to the key places. When the shading/light source is chosen and worked in such that it will further emphasize the key points, the impact/vividness of the piece will become even more powerful.
I will note that, I did not draw these lines as an initial step to drawing Tyranitar. I didn't even think about them when I was making my initial drawing-- it's instinct, second nature. For a lot of artists, seeing how to compose the drawing comes second nature, instinctually-- they don't really think about it. They just "know".
But, this same understanding can be achieved simply by being aware (and drawing/using the lines at first)-- and in time, it becomes instinctual as you continue to use it.
I hope this brief explanation of how to use the Golden Sect will bring something extra to some works around the Studio. :D