1 Put a person in a room facing a window.
2 Let him/her look straight forward.
3 Take a frontal picture of the face using daylight only.
4 Position the face full-image in the center of a square.
5 Define the colour of an average white complexion.
6 Fill the square with this colour exept for the eyes, brows, nose and mouth.
7 Sharpen the remaining features.