Do not use a pick-up line. It will send a girl running back to her friends. Just say hello and introduce yourself.
Ask her questions about herself. Keep them superficial, such as her name and where she works. Do not get too deep during this initial meeting.
Tell a little joke. Keep it clean and, if she is responsive, gently touch her arm.
Lean toward her when speaking. If she responds in kind, move even closer. If she appears shy, don't make her feel uncomfortable by getting too close.
Tease her. Keep it light and friendly, but tease her about something non-personal, such as her drink. Make sure to pause in between these harmless insults to give her time to tease you in return.
Be confident, even when you're not. Girls respond to confidence and this positive reaction will make you feel better about yourself.
Make eye contact. Keep your eyes focused on hers and not other parts of her anatomy.
Keep smiling. It will show her that you are a happy person who is looking to have a good time. Make sure the smile is sincere and not plastic.
Ask for her phone number or email address, or give her yours, if she seems interested.