smile everyone likes a good smile, if your talking to the person smile at them during if your eye flirting wait till your eyes have brocken contact its s good signal that you saw him but are ignoring him just paying attention to whom ever you are with. Biting the lip at apropriate flirty times is a real cannon charger too. Ei if your thinking and you look up and bite lip, listening intensely, being fingered under table, you'll just know when is appropriate