In my country secondary school teachers often use the correction ladder as a tool to keep pupils in line. If a student misbehaves, you look at him. Usually that's enough. If it's not, call out the pupil by name and tell him to behave. If that's not enough, etc. At the end of the ladder, he is temporarily removed from class and is forced to write a letter of "I did x wrong and annoyed the other pupils, I will do y the next time, sorry teacher."

Each time that the student misbehaves, you escalate the correction. You never use the same correction twice on one pupil during one lesson. Instead, you use a harsher correction each time. However, ladders get "reset" to zero after each class.

It's important to be fair and consistent. That means that each pupil climbs the ladder separately: you shouldn't be really harsh on a pupil for her first infraction just because another student has been misbehaving. However, each pupil climbs the same ladder, and the ladder should remain consistent throughout your lessons so that pupils learn to recognize it.

You use the correction ladder for minor misbehavior only. If a child punches another student in the face, then you don't merely look at him sternly. Also, your ladder should be relatively short. If your pupils learn that they can misbehave five times before there are any real consequences, then they'll see that as an invitation to misbehave two or three times. In my experience, however, students don't see a short ladder as an invitation to misbehave a few times for free, because it's stressful to be one correction away from real punishment.

It's to be expected that you have to escalate the ladder to the end (removing a pupil from class) a few times with a new class before the pupils stop shit-testing you as often. This means that the end of the ladder shouldn't be permanent expulsion (or a hard next in the case of a woman), but an unpleasant temporary punishment. (edit: On second thought, here's where dating women differs from teaching pupils. While you can't decide by yourself to permanently expel a student, a ladder for women definitely can include a hard next at the top.)

Once you've escalated all the way a few times, however, your students will see that you looking at them when they're misbehaving means that they're on track to get temporarily removed from class. It makes the lighter corrections carry an implicit threat.

It also puts the pressure and choice on them and not you. A clueless teacher may feel threatened and unsure what to do when a pupil keeps misbehaving despite corrections while the student is having a blast. However, using the correction ladder, the teacher has to spend zero brainpower thinking of a new correction on the fly and the pressure is on the pupil instead. Hey, I'm just following the ladder. If that means I have to punish someone, then I'll punish someone. That's their problem, not mine.

Following the TRP tradition of "women are children," you can this tool on them too. So, what's your correction ladder?

edit: so far, the conversation has been about physical punishment. That's one way to do it, but there are so many more options. For instance, you can place expressing disapproval, withdrawing physically or emotionally, dread game, radio silence, etc on a ladder.