I've been delighting in etiquette tips lately - the stuff you never realise is an issue. Like when people say 'cheers' but don't make eye-contact. I'm a big eye-contact person, and never noticed that some people don't do this, but there you go! Apparently it's important, both for alcoholic and non-alcoholic drinks.
Anyhoo, I was browsing Tiffany's site (the next book is set in New York, and I've idly browsing, just dabbling with possibilities). Apart from lovely pictures of treaty things, they have a small etiquette section for dinner parties. Some are recognisable: It’s not polite to request the wine that you brought as a gift. Some seem quite American: Stand up when an older person enters the room - how wrong could that go - "Why, how old did you think I was? You didn't stand up for Marlene, and she's a year older than me. Really, how old would you say I am?". Shudder shudder. But this one's my favourite:
Bring a gift. But remember, because the hosts are busy, cut flowers are best sent ahead of time or brought in a vase.
Could you be more thoughtful!