Smoking students will lean back against a wall, take a few drags from the cigarette and then douse it, or sit down and smoke. Smoking is most often done in the school bathrooms, but it may be done on campus or in town, in a few relatively sheltered areas. Only clique members smoke, including the girls and the Nerds. If Jimmy points the camera at a smoking pedestrian and they see him, he or she will drop the cigarette.
The Prefects or other authority such as the police won't attempt to bust students who are smoking, despite underaged smoking being illegal. Mechanics for busting smokers were most likely never introduced because Jimmy can't smoke.
Out of all students, however, the Greasers will be seen smoking more commonly, often at night.