1. “I love British accents!”
I’ll begin with my biggest bugbear. Let me just give a quick geography lesson here. Great Britain (or, rather, the United Kingdom) is made up of four countries: England, Scotland, Wales, and Northern Ireland. All of these countries have very distinct national characteristics and very different accents. Within these countries there are even further variances in accent. Like, huge variances. A person from Glasgow will sound absolutely nothing like a person from London.
There is no such thing as a “British accent.” Tell us instead that you like our accent, and don’t insult us by instantly letting on you know nothing about our country and culture.