Is that you in your avatar? Gosh you're lovely! Keep the makeup natural, but play up those cheekbones with a blush. I'm guessing you're around the same age, 15, and I think a fresh face would look best. Use a brown eyeshadow on your crease, with mascara, the blush, and lipgloss. What's your coloring?
As far as the hair, curl it and put it up in a messy twist. You're wearing a halter, so you're going to wanna show your upper back.