A very common one-liner to start a conversation with a woman in a bar or a dancing is: "Don't I know you from somewhere? You seem familiar...". But it is one VERY BAD one-liner. Because a woman obviously doesn't want to look "familiar". She wants to look "special". And because this one-liner is so old and not in the least
original. And what to do if she says NO? Then you are left with the suggestion that, even IF you two had ever met, you are obviously not a man for her to remember. Not a good thing for your confidence...

A much better variant to this one-liner would be: "I don't think I've ever seen you. Because I would surely remember a nice looking woman like you". In this case you stay in charge. You started a conversation and made her a compliment in one single move. That shows balls. And you're not dependent of her answer.

Most of the women will say: "thank you". Then you can immediately offer her a drink. NEVER EVER say: "You're welcome". Because that shows that you where merely making her a compliment and that you don't mean it.

Some women will turn themselves away from you, or hide their face, or start laughing. That's really scary at first. You get the impression that you made a fool of yourself. But NO man is EVER a fool to a decent woman if he made her a nice compliment. In most cases it just means that she is shy and not used to getting compliments. Just apologize with a friendly voice for making her feel uncomfortable.

Give her a few seconds time and she will come back to you. Then offer her a drink. DON'T put your hand on her back or her shoulder to comfort her. It will make things worse!

If she shows no sign at all of coming back to you, just leave her alone without saying a word. And don't start thinking that everyone around has been watching you while you were turned down. If it's crowded, no one has seen a damn thing! Don't leave the bar feeling ashamed. Have a drink and try another woman. Convince yourself as soon as possible that not every woman reacts the way she did.