Choose your product. Decide if you would like your product to exist in "real life" or if it will be as fake as your infomercial is. A product could be anything from a nut grinder to glass cleaner. Obtain or make the product, depending on whether it really exists or your imagination produced it. You will have to be able to demonstrate how the product works to make a convincing infomercial.
Develop your script. Leave room for a demonstration, an explanation of your product and testimonials. Devote time to this part of the process, as the script forms the foundation for your infomercial.
Gather your talent. Recruit a convincing personality for your main actor, and choose several people to give testimonials regarding how the product has altered their lives.
Choose your location for the infomercial shoot. Set the date and time for the shoot, and inform the talent and actors accordingly. You may wish to shoot your testimonials separately, or you could include them in the same shooting time as the main body of the infomercial.
Plan out and shoot the infomercial using close-ups, medium shots and long shots of the product, the main actor and the testimonial providers.
Using an editing program of your choice, edit the shots together. Keep the story moving and the interest level up by including appropriate music and graphics.