Take care of what you have. There is no point in fretting about the fact that you aren't three inches taller, or that your eyes are green and not blue, like you wish. You need to work with what you have.
.Washing once a day is essential. Your face needs to be washed and moisturized once in the morning, and then again in the evening before you go to sleep. Shower often, and remember to shave your legs and under your arms. Be sure to ready a washcloth, body towel, and a floor towel. Make sure you keep your floor towel straight on the floor, and body towel nearby, and absolutely keep your wash cloth in the shower, then take all 3 out when you are done.
.Your hair must be well maintained and kept healthy; you should not dye it an unnatural color. If you do decide to dye your hair, never let your roots show. Whatever hairstyle you wear must be neat, clean, and appropriate for the occasion (i.e. hair in an elastic band for gym is more comfortable, but an up do would be more appropriate for a formal.) You do not need to curl or straighten your hair, although you can if you want to.
.Your nails must be well kept. You must not bite them or let nail polish chip.
.Make-up should be natural during day time events; tinted moisturizer is fantastic, if you have clear skin. A light mineral powder foundation is recommended, if your complexion is blotchy and full of blemishes. A congealer that suits your skin tone is helpful in hiding nasty blemishes, but do not let yourself fall into the 'more is better' trap, because it really isn't; looking like a cake is not getting you any closer to being a proper young lady. Heavy eye make-up should only be worn at night events, as is the case with red or other dark shades of lipstick. However, one should not wear red lipstick with heavy make-up; it needs to be one or the other.
Perfume should be carefully chosen; a classic lighter scent should be worn every day; something heavier for going out, but remember to never wear anything that you feel you don't have the confidence to pull off.
.Eyebrows are a very expressive feature of your face, and should be well maintained. However, over-plucking is not necessary or advised. Your teeth are also very important and often neglected; be sure to brush and floss them at least twice a day. Using mouthwash is also quite effective.