If you are on teaching placement, one of the biggest challenges to overcome is behaviour management. This is just a post on what has worked for me in my teaching experience so far, different things work for everyone but this is just my way of doing things, five years in to my teaching career. (only 35 to go!)
If you have a class from junior infants to second class, behaviour management isn't normally a big issue. Most of the time children may be just a bit excitable and need a gentle reminder or redirection, and positive reinforcement really works. (most of the time)
Sometimes issues may arise in senior classes but of course it completely depends on the class. I find the best way is just to go in and be quite strict for the first week. This is easier said than done when it is your first teaching practice. I remember worrying the night before my first TP thinking HOW am I going to get them to listen to me?! And the first few days were tough but I wasn't long learning I can tell you that much! If children think you're an easy tough they will slack off, I mean wouldn't you have in primary school?!
So, as I said strict no nonsense approach in the first instance, go through the expectations you have for the class, make them very high! Explain whatever behaviour management system you will be using and stick to it, no exceptions! The class teacher will be the best help on this front as he/she will be able to tell you what works for each particular child. I know a lot of teachers use Class Dojo, I have in the past but I don't really like it anymore! I find it very time consuming and maybe a bit over used. A simple group rewards system us best and individual reward systems for those who need it.
If you are not on TP and you are doing the DIP or you are newly qualified, then you can always get the child's parents on board if the behaviour is particularly challenging. It is so important to RECORD EVERYTHING and nip undesirable behaviour in the bud as soon as it starts.