Maybe, she's just not that into you

Opening Lines and Tips Part 1
For the single lads at night clubs/pubs/parties etc

Don't ask which suburb in this fine city she's from.
It slightly smacks of creepy stalkerdom if you think about it. It doesn't tell you anything about her either so why ask that?

Don't ask if she's out with anyone or on her own.
It feels like you're trying to establish if she's alone and an easy target which is also a bit creepy. If you want to ask if she has a boyfriend/girlfriend, well that's a fair question and it certainly makes your intent clear.

Don't assume that because she has answered 'no' to the significant other question that she must be interested in you.
Maybe she's just refreshing honest and polite.

Don't follow her around the venue like a lost puppy dog.
Stalker/creepy/needy. Do not want! This kind of behavior can get you reported to security by the more savvy lady. It's also a great way to ruin any positive conversation or rapport you might have had with the lady earlier in the night.

Don't be drunk or too tipsy.
You talk crap when you're drunk, you splutter, you get too close, you swear. It's very unattractive. Enough said.

Learn to read basic body language.
If she's doing more than one of these:

• avoiding eye contact with you;
• looking around the room a lot or staring off into the distance not at you;
• keeping a physical distance from you;
• keeping her answers to your questions short;
• being evasive in response to your questions;
• folding her arms across herself or has her elbows jutting out at you;
• walking past and completely ignoring you after talking to you earlier;
  

it's because she's not interested and doesn't want to talk to you, but is too polite to tell you to leave her alone! Cut your losses and move on.

I don't know why but most guys who have hit on me at night clubs use those first two questions as opening lines and they DO NOT WORK. Maybe they are the first things to pop into their heads [shrug]
Having worked in retail, sales techniques (ie. 'professional' pick up lines) do not work so well on me.

Being charming and an interesting person to talk to is what matters.
You could ask her about music, art, movies or what she likes to do in her spare time. These are the things that tell you about a person's character and what they will probably enjoy talking about.