Flirting signals can be difficult to read, and in most cases it is the male looking for a positive sign from the female before he decides to talk to her. If the girl is interested but she blushes and retreats back to her friends, then the guy may interpret this as her lack of interest and back off. The female needs to remember that the male is looking for some signal that she is interested in him, so if she wants him to initiate conversation then she will have to fight her shyness and give him a wink or a nod to let him know that he can take the next step.
Flirting can result in acceptance or rejection, and when it results in rejection it can be a sensation similar to physical pain. Fear of rejection prevents many people from initiating flirting, or continuing to flirt after they get what they consider to be confusing signals from the object of their flirtation. The worst that can happen during a rejection is that the other person says no and declines your offer for further conversation. The only way to overcome the fear of rejection is to experience it once in a while and understand how anti-climatic it is--allowing you to better handle rejection the more often you hear it.
Is it Working?
Since the male is expected to pick up on female signals during flirting, it is important for the male to understand what signals to look for that should convince him that his flirting is successful. A female that is interested in the male's flirting will have extended eye contact with the male, and she will continue to glance in his direction to see if he is looking at her. A classic positive signal is a simple smile from her. Whether it be a sheepish grin or a full smile, the smile is a strong positive signal that the flirting is working. Another signal that can be picked up from across the room is when she begins to play with her hair some way while making eye contact.
All of these signals are sent across the room from the female to the male to let him know that she is interested. The male will usually approach the female to see how interested she is after he receives these signals. Some strong positive signals when the male approaches the female are if she initiates physical contact during conversation, and if she laughs at the things he says. These are classic indications that the evening's flirting was successful.