In a word: always wash your face. "There's no way my makeup is not coming off immediately when I'm done wearing it," she said. "The second that it doesn't need to be on my face, my makeup is coming off and I'm making sure there is not one particle of makeup left on my face. I'm really huge on that."
But just because this is Chamberlain's golden rule now, doesn't mean she was this religious about cleansing in the past. "I actually didn't used to be this way. I would go to sleep with my makeup on sometimes and if I'd be hanging out with friends, having a sleepover, I'd be like, eh, I don't need to wash my face and that was a big mistake," she said. "I don't do that anymore. I also don't leave it on longer than it needs to be on. I'm not just like walking around with makeup on my face. The moment it's over, it's over for me. And I'm passionate about that."