Online, I usually run circles around them.
It almost always comes down to them, trying to push a label on to individuals, and to try to force them into a role. I simply tell them people are free to identify however they want, they then go off on a tangent about wanting to be a helicopter or some other nonsense, and I usually reply I don't care what they want to be, it has zero impact on my life.. just like me being transsexual has zero on theirs.
They almost always try to turn it around on me, saying I am trying to take away their free speech or some other nonsense, and I let them know they are the ones trying to impose their views on me, not the other way around. Then they go off on a tangent, spitting out conspiracy nonsense, fueled by paranoia.
It is especially funny when the argument starts out with how they are not transphobic, because they are not afraid of transsexuals, by the end of the argument, they show their true colors. They are terrified of us.
But this is all done online. I don't have to deal with real life bigots yet.