It's All About The Face
Keep an open, friendly expression on your face. If you see someone that interests you, give them a small smile. Smiling lightens your face and makes you appear approachable. When you flirt, use your smile and your eyes. Don't stare for an uncomfortable period of time at the guy you like, but make eye contact for a few seconds so that he will know you are interested in talking with him.
Let Your Body Language Speak
When you're talking with a man you like, lean in toward him a bit. If you're in a crowded bar, you can use the excuse of not being able to hear well as you lean near him. Tilt your head to the side to indicate that you're avidly listening to his conversation. Touch can be a sign of interest, so lightly touch him on the arm or shoulder during the conversation.
Don't be afraid to make the first move. Hold your head up high and enjoy yourself as you flirt. If you're going to a bar, dress your best and know when you arrive that you look good. Stay confident, and when you see someone who catches your attention, offer a smile. Walk over to the girl who interests you with a slow, confident stride and introduce yourself with a simple hello.
You do not need to begin a conversation with an elaborate pickup line; instead, say hello and give your name. Compliment the guy you like. People enjoy hearing compliments. Keep the compliment sincere. Tell him if you like his clothes or his eyes. Don't reveal too much information about yourself too quickly. At first, ask light questions. If you're at a bar, ask if he's heard the band performing there play before or ask for the name of his favorite drink.