Have no expectations. If you go into a given conversation with expectations about how it will end (getting a date or even her phone number, for example), you'll risk coming off as desperate or forcing the conversation. Relax. Take a deep breath. Enjoy the conversation for what it is, and the woman you're talking to will be more likely to respond positively.
As long as you’ve sparked feelings of attraction inside a woman, she will be open to giving you her phone number. One of the keys to meeting women is that you actually move things forward to the next level. For example: Conversation > Phone number, or Conversation > Kiss, or Kiss > Sex. Don’t ever wait for a women to suggest the next move. You’ve got to lead the way by believing in yourself and knowing that if you’re being confident around her, she is naturally going to be feeling attraction for you. The more confidence you allow yourself to feel, the more naturally attracted she will be to you.