With classic silhouettes and quiet details, Vena Cava has granted every girl the much-coveted ability to look effortlessly hip. "We're not interested in loud clothing," says cofounder Sophie Buhai. Though Buhai and partner Lisa Mayock have been smart about building the niche brand through profile-raising collaborations with Gap, Converse, and Uniqlo, their witty personal touch with fans has also spurred Vena Cava's growth. Last summer, Buhai hosted an online garage sale of personal items. (In jest, Mayock's birth certificate, Social- Security card, and self-esteem were also for sale.) At the debut of fall's '90s-inspired collection, Vena Cava distributed a zine -- dubbed 'Zina Cava -- boasting ephemera from Buhai's and Mayock's high-school days. "Our customers are our peers," Buhai says. "You must articulate your culture."