how to talk to girls at nightclubs

Refrain. Nightclubs are for dancing. They are not for talking. They are not for striking up an acquaintance based on the brilliance of your mouth. They are not for leaning close, intimating a whisper, when, really, you are forced to shout. That music playing loud against the walls and hard on the space between you and she, it's there for a reason. It's there for dancing. It's not an excuse for a fumbled line. It's not an excuse for a clumsy line, a tawdry line, a foul and insinuating line.

The following conversation should not occur:

"YOU HAVE NICE MOVES."
(confusion stemming from the fact that your shout is inaudible)
"MOVES. YOURS. NICE.
(tepid smile)
"I HAVE MOVES TOO."
(silence, except for the music that is being shouted over)
"MINE AREN'T MEANT FOR THE DANCE FLOOR. IF YOU KNOW WHAT I MEAN."
(unst-unst-unst-unst)
"GET IT?"

Exceptions:

You are friendly enough with the girl in question to feel no awkwardness in your attempts to be heard, even if your mouth ends up practically inside her ear.

You've been dancing together in a friendly way. She has not pushed you. She hasn't been staring with great concentration at the wall behind your shoulder. Smiles have been exchanged. The music has paused.

Even then you may want to limit yourself to an exchange of names, a brief comment on a song, a (if you're daring) request for a phone number. Don't try to be smart or, worse, sexy. Just be an ordinary human being.

And, don't forget to dance.
----------------------->
And, for fun, you should read: "How To Talk To Girls At Parties" by Neil Gaiman. It contains one of my favorite long sentences in a short story.