Just be confident, introduce yourself to her group of friends and in turn introduce yourself to her just as you would if you joined a new school or when you were very small.
We all dont realise this, but we need to look back at when we were little kids. Did we have this embaressment about talking or 'making friends' with new people that we do nowadays? Remember when your parents used to tell you to go make some friends on holiday and you would just go up to the nearest kid and introduce yourself. Apply this nowadays and you will go far in school.
Do not place her on a pedestal, she is as far as you know, just like every other girl you dont know. Just talk to her, stop focusing on gaming her, game will come naturally if you can do this. Be funny, charming and confident. You need to project happiness, confidence and comfort around people and new people. Command the room.
Dont be awkward, or over stay your welcome when you have had a chat. Just talk to her, make yourself known to her and find something else to do. This shows you are a busy guy. Don't stay too long to chat to her, as if she is new to a place she might start trying to think of you as a friend. You need to charm her and get out of there, dont even worry about getting the number first time around. This is not a club or bar, its school, she will be around.
Oh and don't say cheesy phrases, rehearsed lines or call her pet names. It can come across as wierd in the adult world, its even weirder sounding as a teenager. Just be a cool, confident guy. Hold your head high and be articulate when you speak. You might see the 'jocks' saying things like 'hey sexy', if this isnt you, dont try it, it will go wrong. Just be naturally charming, playful and happy. There are tons of threads on this.
Oh and if you need something to say, how about 'hey I haven't seen you around before, you new here?'. If you get a positive response, which most likely if she is new she will give, then introduce yourself as she most likely will. Let her talk, if shes a talkative girl, otherwise do not talk serious with her, be playful and make a few jokes. She will probably ease up to you and become talkative. DO NOT GIVE MUCH AWAY ABOUT YOURSELF, keep the initial introduction short. You need to be a mystery to her. By giving yourself away to her you will become her friend, simple as.
If you want a situation opener, look for it, but dont look so hard that you are the guy hovering around her doing nothing. If you are around her, keep very busy, busy enough that she wont think you are just hovering looking for a chance to speak to her. If you make eye contact once or twice and she holds it or smiles, you have to go over. If you dont it makes you look not interested or a wimp. Command the room and go over and introduce yourself, you can either say something like 'I havent seen you around before, you new?' or use a situation opener here. After you have had a few lines of conversation then be playful with her. Something I like to do is play a game with them, this is a very good one if you can learn how to do it and project it correctly and always gets a good reaction (
http://www.youtube.com/watch?v=0aWoN8MvGKw).
Just grow a pair, and do it. Nothing bad can come from it, shes either got an initial interest in you or she doesnt. You don't lose either way as if shes not you realised rejection isnt that bad.
