A good visual aid springs to life after its creator has followed some basic steps:
Go back to the outline of your speech and jot down ideas for visual aids. How could a visual aid help clarify an idea? What kind will work best—chart, model, graph, or illustration? Always design a visual aid to perform a specific function. Use visual aids only where they are needed and make sure they are related to the subject. They should not only liven up your speech but also have a purpose.
Write down the essence of the visual aid on a piece of paper and start to work out the way it will look. The paper represents the visual aid; limit yourself to the one or two points you want to emphasize.
Sketch out the visual aid itself. You will give this rough sketch to an artist if you're working with one. Whether you are creating your own visual aids or working with a professional artist, always make a rough sketch before you create your final version.
Avoid clutter; make your visual aids simple and easy to grasp. If you must combine words and type, strive for a good, balanced layout. Each visual aid should have a title, and should cover no more than three main points. If you have more points to make, create additional visual aids. Limit yourself to no more than six lines on each visual aid; less is definitely best!
If you're using numbers and words on the visual aid, make them large and easy to read; take advantage of the ways graphics can reduce the number of words. Make sure each visual aid emphasizes your main ideas.
Use color in three ways: to please the eye, add emphasis, and differentiate one point from another. Even a little bit of color can spruce up a dull visual aid: Underline headings in color and put colored bullets in front of major points. But don't overdo it: A lot of color can lead to confusion. Using too much color is far worse than using too little.
Color has a psychological impact on most people; we are drawn to the colored portions of advertisements and sales letters. Blue and black are both good for headlines; blue is also good for highlighting and underlining. Green implies go ahead and tends to be perceived favorably. Red is an excellent eye-catching accent; however, it is harder to see than the others and implies both stop and losses (red ink).
So when you work out your rough sketches, use color and practice with it. Try out different colors and get reactions from your friends. In other words, work out the bugs before you finish the visual aids.