Find a picture to work from.
Print your image to size on regular computer paper. This technique will not work on a regular glossy 4 x 6 printed photo.
Scribble pencil graphite on the back of your printed picture.
Carefully tape the picture on a piece of paper. You do not want it to move while you are working.
Trace all lines and details on the picture with a sharp pencil or ballpoint pen. Only do outlines of important features.
Before lifting the paper, check that you have traced all important details.
Once you are satisfied with the basic portrait drawing, remove the image.
Trace over your pencil lines with a drawing pen or extra-fine tip marker.
Once you have traced all details use an eraser to get rid of extra pencil lines.