I always resented books that tried to teach a lesson, where the characters are too good: They don't swear, they tell their mothers everything.
Even now, I change my style and clothes from one day to the next, but during high school I blended in. I think a lot of people are that way. I guess that's why I can write about an array of characters.
My biggest fear in writing 'Gossip Girl' was that the characters would sound like stereotypical rich, air-headed heiresses. These were my friends. They were smart and multifaceted. They had interests and passions. They wanted to become lawyers and doctors and writers and filmmakers.
I decided that, if I were to write a teen series, I'd want to set it in a place that was familiar to me - Manhattan, where I'd grown up - and I'd model the characters on myself and my friends.