An interesting question, how to boost ones confidence when approaching and talking to women, and not easily answered... First I'd like to suggest that you think about what confidence is and how it is reflected in your behavior.
I think that confidence is having an unshakeable inner calm and sense of self that is not disturbed by outer influences. If you have those two qualities in your personality it will portray itself as confidence in both how you behave and speak. When you're calm it's easier to joke around and have a good time too.
I've had an inner calm beyond that of most normal people ever since early childhood when I realized I was different from those around me and that only my opinion about myself was what really mattered to me, because who knew me as well as I myself did? What other people thought or told me was only accepted as "truth" when I agreed with the thought, making it almost impossible for those that wanted to influence me in a negative way to have any impact on me as a person. This has made me able to feel secure in who I am and what I think about all sort of things, which I believe is the root to having an inner peace which shows as outer confidence.
Many women, from what I've seen, have the uncanny ability to pick up on the emotional state of the persons that they are interacting with, and if a woman is with someone that is calm and relaxed they will also feel calm. For example, my unflappability and inner calm is something I've heard many women say they find attractive in me. I think that is because if a woman cannot negatively influence the man she interacts with she will most likely see that as strength/confidence in the man and know that the man will not become flustered/shy/wimpy/afraid if an unknown "bad" situation occurs.
If you can have women feel good when they are around you they will naturally want to be with you again. This is something I think is key to getting a woman's number, mail or other contact information and most importantly their wish to meet you again.
I also think that anyone that is easily influenced by anything to a degree that makes them unable to handle their own inner emotional world can never truly feel confident.
I recommend doing some sort of meditation to find inner peace and to learn to know yourself, so that you can remake the things in your personality that does not benefit you.
Learning some things to get control over your own emotions will also be useful. For example, I almost always put a pause on feeling my emotions by thinking about why I feel what I feel when I feel it. This thought-process makes me more likely to not have feelings overwhelm me.
I actually didn't think this post would become this long, but I couldn't stop writing when I began thinking about confidence and its implications. I hope my semi-rant has something worthwhile in it for you.
_________________
Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
"I live in that solitute which is painful in youth, but delicious in the years of maturity." - A. Einstein