Familiarize yourself with Andy Warhol portraits at Andy Warhol Prints (see Resources below).
Photograph yourself or your subject using a digital camera. (You could also use the image of a pop icon like Madonna, Cher, Tom Cruise or Julia Roberts.)
Download your image to a computer and enhance it. You need to be working with a clear, well lit and "in focus" photo.
Print your image in black and white.
Crop your image to create a portrait. To achieve the iconic Andy Warhol portrait look, a head and shoulders shot works best. A Warhol-style pop portrait is about the person, not the background.
Trace your image, concentrating on shapes. Trace the darkest shapes first, then the lightest shapes. Trace the medium gray tones last.
Transfer the traced image onto poster board using graphite transfer paper.
Mix your paint colors. Be outrageous. Warhol used a variety of dramatic, bold colors for his backgrounds and skin tones.
Paint. You can create a monochromatic painting or use up to four colors. The values of your colors should be exactly the same as the values in the photo.
Create more than one portrait and combine them in the same way that Andy Warhol did. An example would be his portraits of Marilyn Monroe.