Learn the pointillist painting technique by first studying and understanding color theory.
Artists and scientists have long studied the origin and relationships of color. Isaac Newton developed the first color diagram in the mid-1600s. There have been many variations to color theory since that time. However, artists tend to adhere to traditional theory based on the concept of three primary colors as the basis for the visible color spectrum.
Red, yellow and blue, the primary colors, cannot be created from any other colors. The "primaries" are the anchors of the color wheel, flanked by the secondary colors created by mixing them. Red and yellow mix to form orange; yellow and blue mix to make green; blue and red mix into purple.
Tertiary colors form when a primary color is mixed with the adjacent secondary color on the wheel. The tertiary colors are: red-orange, yellow-orange, yellow-green, blue-green, blue-purple and red-purple.
Dry media is best for beginning pointillists as it permits the artist to focus less on keeping the brush wet and more on the technique of applying color to the art surface. Oil pastels, soft pastels and crayons are less tedious to use than colored pencils.
Choose white or lightly tinted paper with a good "tooth" for holding color. Use a rigid, flat surface such as a table or drawing board.
Pointillist technique is suitable for still life painting, landscapes or portraiture. Your only concern should be sufficient lighting to ensure that you can see color accurately and clearly. Incandescent light casts a yellowish tint to the environment and alters the perception of blues and violets. Fluorescent lights are blue and cause the eye to see warm colors less vividly. Although it is possible to purchase color corrected light bulbs, natural lighting from a northerly direction is ideal.
Artists are trained to "see" color that is not readily apparent to the casual observer. Place two objects side by side. Notice how light reflects the color of one object into the other. Pointillism technique affords the opportunity to explore reflective color. Instead of painting one object at a time, practice painting "beyond" the object to unify all elements in the painting. Remember that your primary color pigments--red, yellow and blue--are present, in varying amounts, in all that you see.
Recreate the image that you are painting by using red, blue and yellow pastels or crayons to paint color dots. Visualize the color wheel to help you remember how to create the secondary and tertiary shades. Move back from your painting periodically so that your eye will show you where to add more of one color and less of another.