Wherever you are, don't wait for more then three seconds to begin.
Say “Hello” or "Excuse me" and then ask for information or directions or start conversation on situation you are both in (music, whether, traffic, etc.).
Request or offer assistance in doing something.
Introduce yourself and offer her hand with open palm facing slightly up, let's say at 45 degree angle.
When you take her hand to shake it, keep holding on as you continue to talk to her, looking straight in her eyes.
Tell a joke, get her laughing.
Get her alone.
Ask open-ended questions: "How do you like …". Here is an example:
This is where you shut up and listen. Encourage her to speak more by asking more questions in similar manner: "What's important to you in a relationship?"
Stop the conversation early and say something like this:
"I have to go now, but I've really enjoyed this conversation. Why don't you give me your number and we can talk again".
"Have to leave, but why don't we continue this somewhere else and see how much we can enjoy each other's company?".
Suggest a lunch, coffee or date.