Strong Eye Contact
Strong and memorable eye contact is a great, yet subtle form of flirting. With eye contact, it is crucial to be sure not to stare, as staring can be interpreted as creepy. Keep a steady gaze into her eyes for two to four seconds maximum, and then look away. Make sure you look into her eyes in a gentle and natural manner. Good eye contact shows both self-confidence and attraction, and can be a starting point for any flirting interaction.
Flirting doesn't have to be so intense and dramatic at the start. To give the atmosphere a relaxed and friendly vibe, it is important to keep a warm and open smile. This can help to convey interest in another, but it also shows that you are having a great time and are also feeling relaxed with both yourself and with the situation.
Asking questions is another casual yet meaningful way to show flirtatious interest in another person. Avoid giving the person the third degree about her life (with barrages of questions about her family or job, for instance), but make an effort to come across as engaged and interested in whatever she is speaking about, whether it is about an issue in the news or even how bad the weather has been lately.
Body language is key to a successful flirting style. One of the primary elements of good flirting is strong posture. Be careful to avoid slouching. Not only will slouching make it seem like you are not interested in the conversation, it will make you look worse. Make sure to keep your back perfectly straight at all times.
Bring an air of positivity to the conversation. Negativity can be a major turnoff in flirting, so abstain from discussing things that you dislike and shift the conversation to things that you do like. This is particularly beneficial if both of you like the same thing, whether it is a television series, flavor of ice cream, or baseball team.