Make sure you bring a dark pair of sunglasses to the airport with you. When they start the stare-down, put the glasses on and just spend the rest of the time looking in their general direction. (You don't have to be looking directly at them then, as they can't see what you're looking at and won't know the difference.)

If asked to take the sunglasses off, lie and say that you have a medical condition which prevents you from being able to do that.

If asked any other question by them, simply make a disparaging remark back to them. In the past I've preferred commenting about how their blue uniforms make them look like hotel bellhops, or suggesting that their workfare job causes everyone to laugh at them behind their backs. Depending upon the specific interaction, I can usually size up the situation and figure out how to push the right button with them in a few seconds.

The alternative to making fun of them is to simply say nothing back at all and ignore them. Refuse to acknowledge their existence, and only respond directly to a real LEO if one is summoned. You have a right to do so, as saying nothing to any TSA agent is merely an assertion of your Fifth Amendment rights.