In Sixth grade, wear lip gloss, some mascara, and maybe a little bit of pale eyeshadow; don't go too heavy or it may look bad. If you want to try out more types of makeup, keep that for home experiments.
As for clothes, keep it in your comfort level. Bear this in mind: if you are wearing a bra or undershirt, don't let the straps hang out. It doesn't look cool; it just looks sloppy. If you are wearing a short shirt, check in the mirror to see if your stomach hangs out of the bottom. Otherwise, wear something a little bit longer. Also, if your pants are likely to slip, wear a belt. Belts are totally hip now!
* The main point is to keep the makeup light, and the clothes clean cut.
In Seventh grade you are beginning to care a little more what you look like; you might want to try curling your hair a few days a week, and using different hairstyles besides your typical ponytail.
If you are acne prone, try foundation. Remember thet even oily skin can get flaky and that looks horrible with foundation. So try it on weekends first and ask your mother (or someone that uses foundation well) if it looks okay.
In Seventh grade you might want to try eyeliner. But not too much because you don't want to look like a racoon!
Start trying to tie outfits together with accessories. It's good to try new things with your makeup and clothes. But when you try the new things, make sure it looks good on you, not just in the picture or at the store. Check out different stores, and find out if there is a style that suits you.
In eighth grade you are probably getting good at makeup and you know what you like. Try establishing your own hairstyle without looking like everyone else. For example, if everyone has long, layered hair with no bangs, try light wispy bangs and a shorter, layered look.
You might be wearing tighter jeans now and probably starting to get concerned with impressing the guys, so it's safe to try out more mature styles such as a sleek leather blazer, or lower cut necklines. If you are happy with your sports bra, that is totally OK. But it's safe now to check out the actual bra department and wear something that makes you feel pretty - like lace.
Ninth grade: high school! This is a big transition. Now in the same world as seniors, you are going to want to look like the rest of your peers. You should by now have your makeup and hair styles already. Try to update this look a bit, because no one wants to carry the same look they had in middle school. Dramatize a detail in your hair. If its known for it's left side part, part it even deeper. Make a straight style even sleeker and hip. Learn to make youre curls tighter, or looser.
In high school you might want to wear your usual make up during the day, and as you start to go out with friends and boys at night, add a darker shade of eyeliner, or jazz up your lips with something more festive. It's also good to try new shoes, try wearing spikier ankle boots with a pair of hot jeans and a blouse. Chunkier heels aren't as hip as spikes as you get older. Incorporate accessories into your outfit. Buy yourself a bag that's in suede or leather to keep your schoolbooks in, instead of a backpack. You will want to buy yourself a new jacket, and make it your own.
You know what you like, so go and find clothes that fit your style, but crank it up a notch for a more mature feel.