I work in a private school and I wouldn't say I have any sort of low level disruption in my classes.
The children sit, and listen. Then when it is time for them to work, they work.
If they don't do as is required, I will have a word. If it continues, I will have a stronger word.
If that isn't sufficient (and it usually is), last warning will be given. Next infraction, name on the blackboard. Punishment is minutes off golden time (KS2). More chatting = more minutes off.
Continually receiving this punishment would result in a further sanction such as loss of break time or formal detention.
To be honest, if any child was regularly receiving sanctions they would have been flagged as an issue, head of department may well have had a word, if they aren't working hard I have probably already spoken to parents.
And this is all as a result of low level chit chat, not concentrating and not doing what is required.
Unsurprisingly, we don't get any a lot of chair throwing or something else equally as bad. I can't even imagine what I would do if someone threw a chair! Probably go completely bonkers, they'd be in with the school director and we'd be looking at a couple of detentions. I can't even imagine any of our 300 kids ever behaving like that.
We frequently have no kids on detention in a week. Maximum we had this year is I think five in one week, and that was remarked on all round for being particularly shocking!
Good school discipline is a result of good strong structures in place to ensure good school discipline. It's not rocket science.