At the school where I work, one of the teachers with the best classroom management also has the best entrance and exit procedures. Before students even enter into the classroom, she makes them aware of what is expected of them by having them stand in line quietly before they come into the classroom.
She does this daily. Students know what is expected. They know they are to be in a single file line, not talking, and facing forward. It may seem strict, but they do follow through for her. When we line up for lunch, it is without a doubt that our line is the quietest in the hallway, because from the beginning of the year, she set that expectation. Our hallway procedures is to have 6th grade and 7th grade honors line up on the left to go to 1st lunch, and 7th and 8th on the right to go to recess before 2nd lunch. Take a guess who is the loudest?
When these same students return, they are also the ones who are quieter and follow procedures better.
So why does this improve classroom management?
If your students are all over the place in the hall, they will be like that in the classroom. It goes back to expectations. What do you expect from your students? Have you practiced that from the beginning?
Wong talks about practicing your procedures daily for the first few weeks, but I believe there is something to be said about practicing it daily for the year. Expecting it daily. While most will not need that practice after the first month, you will still have some who are nonconformists (nicer way of saying their ADHD is out of control).
Even with exiting the classroom. The procedure should be something that is practiced on a daily basis to make sure that they are exiting just as orderly as they entered.