Accents

Only use an accent where it affects a word's pronunciation:

I'll have the paté, please.

Or when it's actually part of a person, place or book's name:

Arsène Wenger and Beyoncé were seen at the book launch of My life: an exposé, held at Café Déjà Vu.

If it's in an unfamiliar foreign word, the whole thing should also be in italics:

Wolfgang extolled the virtues of spätzle noodles.