Flirting is universal and an essential aspect for human interaction. People, societies and cultures all over the world flirt. School can be a good place to flirt because of the number of girls who are around you; most of the time, you will have girls sitting next to you or near you. However, teachers do not like flirting in their classroom and will probably reprimand you for doing it. There are ways of flirting in school that are subtle enough to get the message across without making a scene.
Begin by finding a girl who is on the same level of attractiveness as you. You have a much better chance of success with someone who is on your level than a girl who is way more attractive than you are.
Try not to show off or impress the girl too hard. Simply try to convey the message that you are interested in her.
Make eye contact with the girl. Having prolonged eye contact indicates intense emotion. A long period of eye contact can show intense interest in love or hostility. If the eye contact does not anger the girl, you will be on the right track.
Observe the girl's posture. Her posture could indicate her interest in your flirting attempts. If her body language is negative, such as folding her arms, you will need to try a different approach. If she leans in your direction, however, that would be a positive sign.
Approach the girl as soon as you can, and start a conversation with her. Ask her how her day is going, and try to follow her answer with another subtle question about her, or answer her if she asks you a question. Keep the conversation light and positive.