Learn from Mom and Dad. Most successful young authors had well-educated, doting parents who encouraged their creativity. Young authors can be honor students, smart kids who play hooky to come home and write or home-schooled savants, but they all have parents, relatives or an adult mentor who spurs them on to great things.
Network with teachers and other writers. Unlike many average college kids and others in their 20s, a successful young author strikes up friendships and business relationships with older teachers, agents and editors, who guide them up the ladder of publishing success. It's never too early to schmooze, and prolific young writers know this.
Develop a niche. Every successful creative person has a style or niche they conquer. Some authors create sword and sorcery characters, others write about their experiences with bitchy fashion magazine editors. A young author needs to find an identity and hone it until their name becomes synonymous with a particular character or writing style.
Write a lot. Create your own rhythm and style--and publishing catalog--by typing novels, short stories, screenplays and learning from your mistakes. Self-publish your work if you must, but persevere and keep writing.
Make friends in high places. The friend can be the proverbial rich uncle or an old classmate who interns at a major publisher, but an astute young author keeps in touch with everyone in the field. That dorky old roommate can end up the editor who "green-lights" your book one day.