Well cocky and funny is by far the best way I see to open up any set or single woman to break the ice. You can start out with tiny jokes and give her what I call the professional laugh.
Do not laugh out loud like a maniac but more around to her level. As far as cockiness goes I always like to act a bit as though I am there in that setting waiting for another woman and have decided to speak to her. You really can't use this method too much. I just use it to open up and engage her to destroy any defenses she might have. Trust me this method works every time. If you do it the wrong way, she will only look at you as her brother or friend figure. You need to practice to perfect it. It took me a couple days of failing to get it right.