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.

Often times if you're bored, the other person is probably bored too.

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.

If it is a cocktail party, I think bringing your partner, husband or wife is fine. To a certain extent, when someone throws a party, they expect to have people over. If it's a seated dinner, though, you should check beforehand. Asking to bring your partner is fair. Asking to bring eight friends from college is not. A good hostess will always accommodate extras and stragglers, but she'll never forget who brought them.

Often times I'll quickly dash off an email or text message when I leave a party. A particularly enjoyable evening, however, that warrants a thank-you note or a phone call. I always say a handwritten note is the ultimate hallmark of a classy woman. But an email is better than nothing.

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.