SO many girl ask me how to do this. I start in the middle, making small strokes out, then make a line up to the end of my brow and bring it back down, making a tiny triangle. Fill in the tiny triangle and then make little strokes in and then from the inner corner to the middle so its all smoothed out.
When applied right, contouring can define your cheekbones and jaw line, reduce the look of a double chin, minimize a larger nose, and lift sagging eyes. Its basically using makeup to highlight and accentuate your features. This is especially important for photos, as the camera tends to pick up shadows and highlights better than the naked eye.