Detentions.
Have a detention rota, do 2 detentions, one for work, one for behaviour.
Behavior detention, all students in one room in silence copying something boring for 30 mins. All staff on a rota so you don't have to think, "I can't give detention I have a meeting tonight".
Work detention with the teacher, at the teacher's convenience to catch up on any missed work.
Don't undermine sanctions.
Eat in the canteen with the students, your mere presence has a positive effect on behaviour.
If you are mentoring a student on NQT and you require a lesson plan 2 days in advance then please read it and make comments that can improve it before the student teaches it.
Again for students NQT don't give ridiculous feedback eg criticise a student for not bringing students into a classroom when you are not there and the school policy is that students cannot let a class in without their mentor/supervisor. Also telling a disabled student the pupils can't see them properly because they don't stand for the entire lesson is not helpful.
Yes those last two were personal, I wasn't the only student told off about not sitting, the other is a ft wheelchair user.
Praise the good kids. Whether it is phone call to parents, a postcard, house points etc. The kid that comes in everyday, works hard but is never top of the class can feel ignored. Individual teachers can give praise but a letter/card/phone call home from a senior member of staff is a huge deal. You don't need to know the child, allow weekly nominations from each department, a card saying, "Ms X has told me how hard you have been working this term, well done" would cost little and reap so much.
And another pet hate. The kid with autism doesn't see extension work as extension, he thinks it's a punishment. He ignores me while I explain to the rest of the class, he is much happier reading the handout and working on his own and frequently completes the work before anyone else. If he spends the last 15 mins reading as a treat for completing work he might not be strictly speaking taking part in the lesson but he is improving his literacy, not having a melt down and feels I'm treating him fairly. In short I am accommodating his SEN.