I live in France and have been teaching here for 15 years. It really depends on where you want to work: in the public education system, private schools for children, language schools for adults, business English language schools etc...
France is not the easiest country to TEFL in. You should basically forget the public schools because the education department are really only interested in teachers who have a french qualification and most of them have never heard of TEFL!
There is work in the bigger cities but the hours and pay are not great, I hear. You would have to work for a couple of schools and juggle contracts to be able to earn a full-time salary. It's a pity really because if ever there was a country in need of some serious English language learning, it'd be France.
I created and work for a non-profit organisation in the French Alps and it works well because Italian is taught in my region in schools, not English. Kids here only begin English when they're about 12 so there is a demand. I also live in a small town about 1OOkms away from the nearest metropole making people feel a little cut off from civilisation and very happy to have English lessons not far from home, like everything else. So, I suppose you could always try that if you decide on France as a TEFL destination!