Second-Hand Quitting

Watching a friend battle addiction can be hard. Helping that friend overcome addiction can be harder. Brown University lists ways to directly intervene or just gently support a friend trying to quit. Almost every "quit smoking" list puts having a support system at the top, so holding out your hand may be just enough to get the cigarette out of your friend's.

Have you ever helped a friend quit smoking? What was the most successful tactic you tried?