Socialite Lauren Davis, Derek Blasberg, and Chloe Sevigny at Barneys New York. Photo: Amy Sussman/Getty Images

"Classy" is one of those words like "intellectual" and 'world-class": if you say you are, then you aren't.

But New York (via St Louis) fashion writer and social butterfly Derek Blasberg has managed to turn the gulf between "class" and "trash" into an entertaining new guide for young people: "Classy: Exceptional Advice For the Extremely Modern Lady."

The tongue-in-chic tome leverages his friendships with fashionable personalities like Emma Watson, Barbara Bush (the former first daughter, not the former first lady), and the Olsen twins to offer modern social advice for young folk. On Tuesday night, host Chloë Sevigny and a gaggle of socialites dressed by Burberry (Lily Aldridge, Julia Restoin Roitfeld, Leigh Lezark, Byrdie Bell and Jen Brill) helped launch the book at Barneys on Madison Ave.

Blasberg told StyleList: "A lot of young girls don't have the best role models in the media. It's very hard to explain how important intimacy is if the image of it is drunk girls falling off the back of a bus to compete on a TV show for some fallen 80s music star's affections."

The book offers fashion, etiquette and hosting as well as relationship advice. (The most important single nugget according to the author? "Always wear underwear.")

Also at the party was Barneys' creative director (and author, and TV personality) Simon Doonan. "I told Derek to channel Jackie Collins," Doonan said. "Just sit behind that desk, sign copies of the book, and channel Jackie Collins."

See what Doonan had to say about spring fashion last month.