Take another look at Marlene Dietrich. Yes, she had naturally defined cheekbones, but she did have some help with contouring. Put a subtle flush of rosiness on the cheekbones. Not much, though. Think of a hand-tinted sepia photograph where the color is washed out. Then, take a medium/light matte brown eyeshadow or bronzer and blend it underneath your cheekbones to bring them out. It’s important that you blend it well, or you’ll get streaks on your face. No zebra cheeks, please!