From my experience on prac, I cannot emphasise the importance of routines and consistency enough. Having a routine for entering and exiting the classroom is particularly important, because students will know what to expect, and hence know when they have done the wrong thing. It also helps prevent potential behaviour management issues for the same reason. If you explicitly teach the rules and routines to the students, you are teaching them how to behave appropriately. It helps enormously if the entire school has the same routines for students in every class and with every teacher, but where this isn’t possible, you can at least implement one in your own classroom for the benefit of yourself and your students.
A possible routine for entry could be students are to get their book (for the lesson), pens and school diary out before they come into the classroom. This essentially means that they are to enter the room prepared to learn – if they have the correct equipment, they should be more likely to enter the room in the right frame of mind. Hopefully.
A possible routine for exit could be chairs behind desks, and stand behind chairs. This should include a general tidy up of the classroom as a courtesy to the next class, and to emphasise the importance of taking pride in their school.
Why is this so important? As teachers, it is crucial that you are seen by your students as being impartial and fair. If you change the routine or change the rules every time you see your class, they will not know what to expect, and they will not have appropriate rules and behaviour routines reinforced. And even more importantly, you need to be consistent and fair with each and every student. Treating a student in a manner that can be correctly perceived as unfair by another student will simply teach that student that there is no point behaving appropriately, or there is no point putting in the effort to learn or complete their classwork.
Remember – students always notice what you don’t want them to notice, remember what you don’t want them to remember, and don’t remember the stuff you do want them to remember! So behave transparently at all times!