How to Ask for a Phone Number
1. Approach the woman. Remember that eye contact and a gentle smile are crucial in appearing friendly.
2. Enter the conversation with a compliment, then introduce yourself. Try not to be too cute with your delivery.
3. Talk. You'll get a strong sense of whether or not, she would be willing to give you a phone number. If there's no eye contact or smile coming your way, and you're really making a solid effort, then maybe you should abort the mission.
4. Ask for the number. Try not to be pushy, and show respect for the person's private information. Avoid "how about giving me your number?" and go with "It would be great to get to know you better. Is there a number where I can reach you?"
5. Offer your own phone number after getting hers, if you feel comfortable doing so. Do this even if the woman denies giving you hers since some women are not comfortable with giving out their numbers.