I think the sort of person you want at a party is someone who is self-aware, polite and has a basic knowledge of table manners. And that goes for both men and women.

If you are going to worry all night, you should let the hostess know that you're coming for cocktails and leaving when everyone sits down for dinner. If you do need to call to check in, people will understand, but excuse yourself from the table and head to the ladies room to do it.

I grew up in the Midwest, so I have sort of an honorable moral code. But I moved to a city and joined a sort of fast crowd. A lot of people who grew up in the city sort of arent aware of manners and other ways of life and common decency.

With her first Oscar nomination for her portrayal of Lisbeth Salander in The Girl with the Dragon Tattoo, Rooney Mara gave fashion fans a new Gothic-chic muse.

Talking, texting or tweeting on your phone is the worst in any social situation. I went to a lunch during Paris Fashion Week, and I managed to steal a few moments with Lee Radziwill - who I think is perhaps the classiest woman alive - and she said this is her biggest pet peeve too. So I'm in good company.

Getting last-minute cancellations can put a black cloud over an event before it has even started. If it's a large, casual cocktail party, then I'll often not say anything until the next day. But if you're not able to make it to a small, seated dinner, you have to call the host - there's nothing worse than an empty chair at a table.

A good party is one that is designed to entertain and bond friends. The bad parties I've been to are the ones that are held to impress other people.