What would be the best way to get my underage brother to stop smoking?

Stop smoking: If a patient is unwilling, or uninterested in quiting smoking it is very difficult. The peer pressure to smoke is huge, and nicotine is one of the most addictive substances on earth, period. Education as to the long term effects often do not phase a young person who feels invincible. Try educating on short term effects like the smell, teeth staining, bad breath, stained fingers, etc.

Trick question. Now.: the answer is to get him to stop as soon as possible. Every cigarette adds a little bit to the long term health consequences. I think the numbers show that every cigarette smoked reduces your life expectancy by seven minutes.