When pupils come to her class, they line up quietly outside the room, if there's space. She stands by the door and greets them as they enter. Mostly she'll say something friendly, or chat about what went well last lesson, but she'll also give little reminders, perhaps about uniform. She's saying, "You're in my room now, not in the playground - my rules apply."
As pupils move to their seats, they walk past the texts, folders and exercise books they need for the lesson, laid out so they can easily find their own, and they take what they need. They take their equipment, including their planner, from their bags, put it on their desks, then put bags and coats in safe places where no one can fall over them. Standing quietly behind their chairs, they wait for her welcome, and sit down for the register.
She's a mistress of multi-tasking and uses the register for more than just recording attendance. If there's homework to be handed in, her pupils will answer, "Yes, Miss, Yes" or "Yes, Miss, No" - one "Yes" to say they're present, the second to say they've brought their homework. She sometimes uses the second "Yes" to check equipment - pen, pencil, ruler. She can use the register to control movement. If pupils are to go somewhere immediately after the register, they move when their name has been called.
Pupils aren't sitting doing nothing. They will be tackling a task on the whiteboard, or copying learning objectives into their books. They will be looking at the timeline on the board as well, that tells them how long they will be spending on each activity - especially useful in the primary classroom to help pupils grasp the structure of the coming day. There's always something for pupils to do as they come in, which is important when they're arriving from different places over several minutes. When everyone's present, she signals the start of the lesson by raising her hand and saying, "Ready to learn?". Pupils raise their hands, and the lesson begins.
As the lesson progresses, one or two pupils, without asking, move about the room to sharpen a pencil or to collect paper. They have agreed a set of simple rules and know that some things don't need the teacher's permission.
If they have to form groups, or reorganise the seating to see a TV screen, there's no fuss because they've practised the routine before.
When her pupils are on task, the teacher knows immediately who needs help without their having to wave their hands or call out. Every pupil has three cards: green for "I'm OK", yellow for "I'm not sure how to do this" and red for "I need help", and they display one of them on the desk - instant visual feedback.
A lot of the signals the teacher uses are non-verbal. She sometimes uses a bell to signal "Pens down, look this way". She's always giving time cues, and has a kitchen timer that pupils can see and hear. If a task is going to take 10 minutes, that's 10 real minutes, not "teacher" minutes.
She brings her lessons to an end in time for the winding-up tasks with folders and books returned to their proper places, homework in planners, then her pupils stand behind their desks and run through a routine of stretching, so that they leave calm and refreshed.
Of course, that's an idealised picture, but it reflects good organisation, where pupils feel secure and responsible for their own learning. Try it yourself, you've got nothing to lose but your stress.