Eyeliner. Notice how there's a hint of blue on her lower lids...and she has blue eyes. Traditionally you go opposite in eye makeup colors (blue eyes get neutral colors, brown gets jewel tones), but I have blue eyes and do this on occasion. It really makes them pop!
Very good eye tutorial. I love the graduation of color and drama. I think this can be a daytime look or a night-time look because it's so balanced with peachy cheeks and lips.