It's just not logically possible. I had a friend, I won't say his name, he didn't smoke in school of course, but you could smell it. And you just knew by even looking at him that he smoked a lot. I think a miracle cure for peer pressure would be the only way to stop kids from smoking. Other than that, I don't think there's anything you can do.
Advertising does nothing.
Nobody looks at the ads. Everybody looks at what everybody else is smoking at their school. And it just becomes a habit, and eventually it becomes addictive. Also, for a lot of people, it looks cool. It becomes addictive because most people don't understand that until they've started.