There are many strategies for dealing with misbehavior in the classroom. They can focus on reward and punishment, assuming a more dominant role, Time Outs, withdrawing desirable activities or, in the worst case scenario, removal of the problem children from the classroom.
In reward and punishment systems, students are offered bribes for their complacency. Black stars counteract gold stars, popsicle sticks gracing the offending student's name are added to a bad choices cup, or minutes are taken from recess time. The loss of recess is probably the worst tool choice as it reduces the amount of exercise and free play that the disruptive child gets and they probably need it more than other students. In each of these cases, students must decide for themselves if the offending action is worth the punishment or loss. If the price isn't high enough, the behavior will continue. If the punishment is too harsh, the student will learn injustice. Since none of these options addresses the cause of the misbehavior, they are doomed to failure, sooner or later.
When a teacher assumes a more dominant role, whether by raising their voice, getting angry or voicing threats, most students will comply initially. In fact, the entire class will be subdued for a while. Unfortunately, the more submissive students will now be fearful, and the more aggressive students will have learned that they can "push teacher's buttons." The students who tend to cause problems in the first place will use this information to torment and harass their teacher for as long as they can. Many teachers have experienced "rough years" when this occurs. Even worse, it ignores the obvious clue that the disruptive student probably comes from a home with lots of yelling (and other problems) and more yelling or threats are the last thing they need.
Time Outs are equally useless. By putting a student in Time Out, they are withdrawn from instruction and miss out on learning. Instead of using the incident to teach better choices for everyone involved, students learn they can manipulate the teacher get out of doing work they probably felt overwhelmed by in the first place. It's one thing to ask a student if they need a few minutes to regain their composure, it's utterly futile to simply park them in a corner to "think about what they did." Disruptive students have unmet needs and it is the job of the adult to find out what those needs are and how to help the child learn to make better choices.
Obviously, sending an unruly student to the principal's office will eliminate the problem. It also interrupts the learning of the offending student. It also teaches them that all they have to do is "act up" to get out of the room. Removal from the room should always be a "last resort" for a professional educator.
Less common, but far more effective, both in the short and long term, is enforcing a concept I call, "Responsibility is the Price of Freedom." This means that the teacher will have to know their students well enough to understand what leads to misbehavior and nip it in the proverbial bud, before things get out of control. When a teacher loses control of a classroom, everyone loses. By observing and noting the developmental levels of each of their students, knowing how they handle different situations, a good teacher can manage the classroom in such a way that most problems are prevented. Students need to know that certain behaviors will not be tolerated and that there will be swift and appropriate repercussions for misbehavior. A student guilty of plagiarism, for example, may be required to present a report to the class on the subject. A student who steals may be required to leave their backpack in their locker. Students who fail to turn in their work may be required to do it in study hall after school.
The techniques are too many to list but the basic method for successfully managing a classroom is for the teacher to be aware of and connected to their students. Incidents that do occur should be treated as opportunities to educate students in the social skills that so many people are lacking. By educating instead of punishing, teachers show their students that they are respected as individuals. When students feel cared about and respected, they are less likely to act out in the classroom.