Choose or take a portrait of yourself, or have a friend take it for you. A well-lit image in front of a dark, simple background will work best.
Open the picture in a image editor, such as Adobe Photoshop or the free Windows application Paint.
Convert the image to 64 colors.
Resize the image to 10 percent of its original size using "Nearest Neighbor" sampling.
Resize the image to 1000 percent of the new size using "Nearest Neighbor" sampling. This will restore the image to its original size and produce the characteristic blocky look of 8-bit graphics.