Non-verbal cues are a powerful form of communication. When you flirt, use your body language to let him know you are available and interested in him.  To show that you are available, keep your chest, torso, and abdomen open. Avoid crossing your arms in front of your chest. Also, make time to be with guys and be one who is including. Following the popular girls or only listening to their opinions isn't attractive at all. Remember, just because your friend doesn't like someone, doesn't mean you should say no. Be inclusive with your friends and try to include everyone. To show that you are trustworthy, keep your hands visible. Avoid placing them in pockets or under a table. To showcase your sexuality, expose your neck. Tilt your head back slightly as you laugh.  To get or keep his attention, graze his arm. The human touch releases hormones that make you feel connected to the other person. In order to form a genuine connection with a guy, your conversations need to move beyond small talk to more meaningful topics. During your conversations, make an effort to be vulnerable—share your interests, show him your goofy side, and tell him your fears.  When people discuss their passions, they light up, feel happier, and instantly become more attractive to those around them. Furthermore, they subconsciously associate those positive vibes with the people around them.  Throughout the conversation, maintain eye contact. It not only lets him know you are listening, but it can actually make him more attracted to you.  Compliment him for something that is clearly important to him, such as his determination to succeed in school or in a sport. Clingy girls can bore or overwhelm guys. However, playing hard to get will not help you seem "mysterious". You don't have to be intentionally elusive and vague from time to time for someone to be interested in you. One thing is for sure, though: if he is interested in you, he will put in the effort to capture your attention. Boys are fascinated by independent girls. Demonstrate to him that...

TL;DR in Vietnamese:
Trở thành chuyên gia về ngôn ngữ cơ thể. Khuyến khích chàng tham gia cuộc trò chuyện có ý nghĩa. Đừng bao giờ tỏ ra bạn không phải là người dễ chinh phục. Duy trì tính độc lập của bạn.