Hey i actually know about this one. I actually only had 1 girlfriend throughout high school because of my ridiculously high standards, so i think i'll be able to offer you some advice.
1.)Make sure you like her. i've felt that way about a few people, and the one i went out with ended up being a tremendous disappointment. It's important to realize that people act very differently in public then they do when they are alone with you. Otherwise, when you do finally get the girl, you don't want her. (I know this sounds stupid, but seriously)
2.)Be direct. In almost all cases, it's very obvious when somebody is attracted to somebody else. the longer you are trapped in this state of everybody knowing that you like her, but you not doing anything about it, the lower her opinion of you goes. (I know this one quite well)
3.)Don't try to sabotage her relationship with the other dude. if he or she finds out it was you, you will be in a bad place. However, if she is not in a very committed relationship with that person, she might leave him for you. be careful bout this part. patience is a virtue
4.)Confidence. = huge appeal for the ladies
5.)Don't write a poem, or suggest any form of love between you. I have seen a man get his nose broken, because he wrote a love poem to a girl he didn't know. start small, with something like a movie, and then look back at suggestion #1. then come ask the escapist again, cuz i can't help you much after that.
Edit: im gonna change can't to won't, because i don't want to have to explain the birds and bees to a freshman