One thing you can do is to scan a picture in, putting it in as a second layer in Photoshop and stretch it around so it fits the basic template in the eyes, nose, and mouth areas. (Keep the opacity around 50-60% so you can see underneath.) The sides won't match, so use the smudge function to spread the color out to the sides. You can find some decent pictures on site for body builders, actors, and models.