Flirting is also about body language. When they say something surprising, give them an exaggerated raising of the eyebrows, followed by a rapid lowering of them. If they say something suggestive, offer them a coy smile, with a tilting of the head downward, partially averting the eyes, perhaps ending the movement with a hand over the mouth. Exposing your neck by turning your head so that the side of your neck is bared is also very flirty. For the more aggressive females leaning forward with your breasts held out or showing more leg is also a tactic.