Smiling makes all the difference. Smiling shows you were happy before you met her. Smiling gives her the idea that you are living your own life, you seem to be having fun doing it, and maybe she would like to be a part of the fun. Girls want to feel alive and guys with a scowl on their face will likely never even be given the opportunity to talk to her to begin with. No one wants to be around someone that looks bored to death. Sometimes we may come across as serious or intense by getting caught up in our own thoughts by thinking of what to say next, or overanalyzing a past approach. Being caught up in our own thoughts keeps us from living in the moment and enjoying the things around us RIGHT NOW. You don’t need to be happy to smile, but you need to smile to be happy. Next time you make eye contact with a girl, don’t think, just smile. It will make all the difference.