Composition is a very important part of the painting process. A good composition makes your painting more pleasing to the viewer and will enhance your chances to sell more paintings. Let me start by suggesting that you use a pencil to draw a very light vertical line down the center of the paper and likewise, draw a line horizontally through the center of the paper. This will help you avoid placing objects of importance in the center of the painting. The other reason for the lines is to help you from ending or starting object at those lines such as a horizon line or the edge of a tree or building.
(Example) Avoid having your horizon line in the middle of the paper, but rather have it no more than one third of the way from the top or bottom of the paper. An example for the vertical line is do not have the edge of a tree or building stop or start on the vertical center line.
Have the painting set up so you have three planes: something in the foreground, middle ground and background. This gives the painting depth and allows the viewer to walk into the scene.
When painting each corner area should be different. This avoids repetitiveness. When painting or repeating objects, such as buildings or trees, have different shapes and colors. As an example, when painting two trees in the foreground, have one warm in color and one cool. Have one thick and one thinner or one slightly closer in the scene. Overlap buildings to improve interests and design. Add life to the scene with people, animals or birds. Place your center of interest slightly left or right of the center line and slightly above or below the horizon line. Try to have objects such as the tops of trees or sails go out of the frame. Clouds also should go out the sides or top of the frame. This will give your painting a more realistic and professional appearance. When placing objects in the foreground, have trees and fence posts end above the horizon line as this will give you more depth and better perspective in the scene.
After completing a painting take a few days or even a week to study the painting and turn it sideways and upside down. This will help you see little things more clearly. Ask a couple friends and fellow artist to critique your painting. By following my suggestions in this article over and over you can’t help but to become a happier and more skilled artist.