Article in English: When you talk with them, don't get super excited or start acting weird. Just keep calm. They're a normal person just like you. Act natural and they'll find it much easier to interact with you. Greet them every now and then, at first warmly, then a bit more flirtatiously. Say hi in the halls or talk to them a bit. Smile at your crush and make eye contact, but don't be creepy about it. For example, if you do not know your crush very well, get to know him/her slowly (Asking them for the time, talking about a book they are reading, etc.). If they are a friend, start flirting slightly. When conversing with your crush, make sure that you spend at least as much time listening as you do talking. Don't send them a bunch of notes or hang around after school and wait for them. Don't get their phone number from other people or do any kind of stalking. This will make them not want to talk with you or spend any time with you. Think about how your actions will really look to them, especially if they don't share your feelings.

Summary in Indonesian:
Tetap tenang. Berbicaralah! Bersikap ramah. Dengarkan mereka. Jangan menakuti mereka atau bertingkah terlalu aneh.