Eye the babe and maintain steady glances throughout the evening. Notice if she is looking your way as well. Have a buddy let you know if she seems interested in you as well.
Walk over to the babe very casually and initiate an interesting conversation. Avoid using some pick up lines because they generally are corny and babes do not like this.
Compliment the babe on her eyes, hair, or any accessories that she is wearing. Girls like when guys notice things beyond body shape and curvatures. Ask her questions about the jewelry she is wearing. This can also give you insight if she has a significant other or not.
Be yourself. Do not attempt to act like someone you are not and do not lie about yourself. If this initial conversation turns into something good, you will be starting out your new relationship with lies.
Listen to the babe and acknowledge what she is saying. Take note of the small things that she brings up in conversation. If she says that she likes peanut candies, buy her a bag if you happen to score a date with her.
Begin to get to know her as a friend. Show her how caring you can be and that you can offer many things to her in life.