To beat the French in terms of some of their undeniable national traits such as irreverence, disparagement, and belittlement, which every Frenchman or Frenchwoman will eventually display in their words and actions.
You should be smart ahead of time and call out these snail-eating motherfuckers for their supercilious behavior. Do not be polite or civil to them. Treat them just like they would treat you: like absolute dirt.
Anyone who has ever been belittled by a condescending French jerk knows exactly what I mean. Don't let it get to you. Stand your ground. This behavior is second nature to French people, just like breathing. Give them a taste of their own medicine.
However, rather than using words, you need to display your contempt for the French through visible actions. You will "outfrench" the French when you can beat them in their own national pastime of condescending power plays
Outfrench the douchebags from other countries only if they deserve it. With the French, it's game on no matter where in the world you run into these Gallic deceivers.
(At a tourist resort)
Me: "So, where you're from?"
Dude: "France!"
Me: (falls silent and leaves immediately)
Dude: "What happened?"
Passerby: "Well, mon lapin (my rabbit). You just got outfrenched by someone who knows talking to you people is a waste of time for him."