If you want to master photography, master light. This great tutorial shows how manipulating the position of lights creates both dimension and texture in an image.
The geography of a person's face is largely what determines their unique appearance, and it's precisely that that causes photographers to pay so much attention to highlights and shadows, the differentials that recreate that three-dimensional topography in a two-dimensional medium. Jay P. Morgan makes several salient points in this video that you should keep in mind whenever designing lighting:
- Moving light off-axis (whether laterally or vertically) creates dimension and texture (this is why photographers abhor on-camera flash).
- When working outdoors with the sun, you'll need to maneuver your subject instead of the light source to find the correct angle to bring out your desired dimension with a complementary background.
- When working with subjects whose texture you wish to accentuate, pay attention to the angle of your light, possibly moving it to extremes.
- When using more than one light, be careful not to create multiple competing key lights unless desired, as this will result in multiple sets of shadows that make for an unnatural look.
If you want to go more in depth on how to light faces, be sure to check out "Peter Hurley: Illuminating the Face."