Subject Placement

The rule of thirds is one of the most important and often referenced rules of subject placement.

Imagine that your rendering canvas is divided into thirds, both horizontally and vertically.

The rule of thirds says to align the center of interest with one of the points where those lines cross. That means the center of interest is one third of the way “into” the picture space – from either the top or bottom, and from either the left or right; it’s not in the middle.

In the above illustration my subject placement, which is my center of interest, is the front entrance.  Notice how I placed my center of interest where the bottom right lines cross?

Counterpoint

You can improve the rendering composition by creating a counterpoint. If you place the center of interest in the thirds position, you can place a secondary focal point at the diagonally opposite thirds position.

Horizons

A natural extension to the rule of thirds is to place your horizon line along the one-third (bottom line) or two-third (top line) of the grid, rather than in the middle. 

Whether you place the horizon closer to the top or closer to the bottom of the picture space, depends on which you want to emphasize more: the land or the sky. If you have a dramatic sky, by all means, give it two thirds of the picture space!

Again, in the above example, I placed the horizon line on the bottom one third....