Flirting is simply a way of narrowing the physical space between you and the other person, letting him know that you want to approach him and inviting him to do the same.
-Smile.
Nothing is more flirtatious than a smile that can hide so many things.
Extended eye contact.
By making and maintaining eye contact you show the man in front of you that you are focused, confident and interested in what he is doing and saying. The eyes show everything.
-Make a small compliment.
There is no clearer indication that you are romantically interested in someone than to compliment (but without exaggerating).
-Take the wheel.
Give the conversation the direction you want. If you expect him to call you, give your number, if you want to get it, give yours.
-Behave elegantly.
If he is not interested or is already in a relationship, hold your position and just pretend you were not flirting at all.
Source: Elite Daily