If the message you intend to send is "I am secure in my status. The attacker's pathetic attempts at reducing my status are beneath my notice.", what should you do?

Ignoring the attempts is a good default. It gives a decent payoff while being easy to implement. More advanced alternatives are the witty, incisive comeback or the smooth, delicately calibrated communication of contempt for the attacker to the witnesses. In the latter case especially body language is the critical component.