If you see a girl you like across a crowded room, try catching her gaze and holding it for about a second. Look away briefly before looking back at her. If she returns your gaze--and better still, if she smiles--it could be a sign that she is interested in you. Walk up to her and ask, "Where has your boyfriend gone?" This is an open question, it cannot be answered with a simple yes or no. Also you will find out straight away if she is single or not.
When you walk or take a drink, or make any movement, use a smooth, slow, even motion. This will give you an air of confidence and suggest that you are in control. Ask her, " How many times have you been to this club?" If she says, "never," you can ask where she normally goes out.
Be careful not to stand too close too soon. If you see a guy you like, walking up too close can make him feel uncomfortable. Wait until he leans in to talk to you as a signal that it is OK to get close. Ask him, "Do you think men should always make the first move?" If he does think men should make the first move, he will have forgotten that you started the conversation by the time he explains why.
You don't have to grin like a madman, but a smile goes a long way toward putting someone at ease. It also shows that you are happy and relaxed. Smile at a girl you fancy and see if she smiles back. If she does, ask "Do you mind if I tell you that you have a really nice smile?" If she says "No," then say, "You have a really nice smile." If she says "Yes, I do mind," answer, "That's too bad, because you have a really nice smile."
Try to synchronize your movements with the person with whom you are trying to flirt. Take a drink at the same time he does and smile when he does, but try not to make it too obvious. If you are both getting along well, this should happen naturally and is a good signal that there is some chemistry between you. This is a good time to say, "Look, you don't have to be shy, you can ask for my number."
Get this wrong and you could end up with a drink thrown in your face. Try touching the arm of your potential mate to emphasize a joke, or when you ask her what she is drinking. Never touch in a more personal way until you are sure that that kind of attention is welcome. Ask her, "What are you drinking? I'll get you a refill after this dance." If she says OK, take her to the dance floor.
Inject some interest into your voice and avoid a clipped, monotone style of speaking. Talk in low tones and raise the last syllable of a sentence to add interest to your speech. Don't overdo it though, or you may end up sounding like a copy cat James Bond. "What's a nice girl like you doing all alone in a place like this?" may sound like an old line but can work if delivered with style and humor.
Make sure your movements don't make you look apprehensive or nervous. Use bold gestures slightly away from your body. Do not keep your hands in your pockets or clasp them together. Ask her, "If you were ice cream, which flavor would you be?" You then say that her flavor is your favorite.
Nod and keep regular eye contact when someone you like is talking to you. Try not to interrupt him or look bored with the conversation. Ask, "Hey, do you want to carry on this conversation somewhere a little more relaxed?"
Take turns talking. Allow the person you are flirting with time to speak before you begin talking again. You should both be talking around the same amount to each other. If you are doing all the talking then she may not be interested. Try asking, "Later on, would you like to have a dance with me?" If she says yes, then at any point in the evening you can say, "Its time for our dance now."