I suggest playing up your eyes since they seem to be your best feature. Apply a deep brown liquid eyeliner along your upper lashes. Pick out an eyeshadow palette that you like for your lids and apply the lightest shade on the entire lid up to your browbone, then take the darker shade and shade it into the crease. Be sure to blend, blend, blend. If you want a stronger look, apply a pencil liner to the bottom lids and smudge the line with your finger so it looks most natural.
I like the way a white eyeliner applied at the inside corner of the eye makes eyes pop. That's a trick all the makeup artists use.
Apply a couple coats of dark brown or black mascara.
Make sure your brows are cleaned up, either with a professional wax or a tweeze. This will do wonders for your look. Too many girls make the mistake of not cleaning up their brow line.
I also strongly suggest playing up your pale skin with a pink blush. If you want to look "tan," apply bronzer on your forehead, cheeks and nose, all the places where the sun hits.
If you have oily skin, apply powder and keep blotting papers in your purse. These papers soak up oils without ruining your makeup. If you have dry skin (few teens do), sweep a moisturizer over your face before you apply the bronzer and blush. The dewy look is youthful.
Keep lips light so they don't overpower your eyes. If you want color, try a pink lip liner and shade lips in. The color lasts longer than lipstick. Sweep a gloss over lips and you're good to go.