According to researches reported in the Personality and Social Psychology Bulletin, we are more attracted to people who look like us.
This is the main concept behind Facilyzer, a face analyzing algorithm, that maps the ratios of a few key facial features (for example the distance between the nose and the mouth), then compares it to a database of more than 1000 pornstars, and lists the ones with the most similar proportions. It does not, however, account for colors or finer details, such as the shape of the lips, for it would severely increase the length of each analysis.
Choose a picture where you are facing the camera, and not wearing any glasses, or having too much hair in your face. Smiling can also help the scan.