Get Caught Looking
The natural reaction is to quickly look away when the object of your desires notices your eyes on her. However, when flirting is your primary goal, give this concept a little twist to show her your interest. Instead of concealing the fact that you are looking, let her catch you and then offer a smile before slowly turning away. This is a polite, subtle way to demonstrate your interest without having to get close to her or open your mouth.
Make Yourself Interesting to Others
The real flirting experts know how to draw attention without making outward efforts. By making yourself stand out in the right environments, you will find yourself with a considerable number of flirting opportunities without having to initiate any contact on your own doing. To make sure you are giving others a good reason to approach you, simply use a little creativity and be yourself, like putting together a striking outfit that makes a statement about your personality or engaging in a hobby socially.
Master Small Talk
Great conversationalists have more success flirting than those who struggle finding the right things to say, and the only way to improve your communication skills is to practice. Practice starting up conversations with strangers every chance you get to hone your skills. It doesn't matter who you talk to when you practice--just find a target and see where it goes. This way, when you find yourself in a situation with someone you are interested in, talking to him will seem natural.
Stop at a High Point
Develop a good sense of when to stop flirting. Done properly, flirting is an innocent exchange between two people letting the other know their level of interest. Ideally, flirting is brief, and if you overstay your welcome, you may ruin a good experience for both of you. If you think your flirtations are getting extremely positive responses, attempt to make a more direct advance by setting up a date or making some form of future plans. Otherwise, politely excuse yourself before the flirting gets boring.