Keep it simple. Too many colors and graphics can make your billboard appear messy and complicated. For a billboard ad to be effective, it must be able to get its message across to drivers who only view it for a few seconds.
Place a photo of your product prominently on the billboard. The views should be able to tell at a glance exactly what you are advertising. If you are advertising a computer business, there should be a large computer graphic on the billboard. If you are advertising a company which provides services, such as a spa, you should have a photo of a person receiving your services on the sign.
Make your billboard ad stand out. Make sure that you check the area where your billboard is placed before designing your ad. Design your billboard ad so that it does not blend it with the surrounding area. If your billboard is placed on the side of a highway which is surrounded with greenery, you should not use green as your billboard's main color.
Use fonts that are easy to read when creating your billboard advertisement. Place no more than a few words on the billboard so that people who are driving by will be able to easily read it in a few seconds. Use a short message that is easy to remember and that is clearly associated with the product you are selling.