Actually, well before the night before the first day of school consider how you want your classroom to run. What will it look like? What will it sound like? What will it feel like? What will it smell like? What will it 'taste' like? Feel, smell, and 'taste' are used here to focus on the experience of the students. After being in your classroom for 50 to 80 minutes, how will they remember the experience?
What happens when the students enter the room? How will you check attendance? What are your expectations for the day, the week, and the year? How will homework, quizzes, and tests be handled? What will be your routine for class discussions? How will you handle student needs (e.g. going to the bathroom)? How will you handle unexpected interruptions? How will the class end?
Develop policies and routines which will support how you want your classroom to run. Teach and reteach these policies and routines until the students know what to do. Ask for student feedback and be flexible enough to make changes. For example, recently my students asked me to change where I write the day's agenda and to spend more time discussing homework assignments. Done!
Describe the look, sound, feel, smell, and 'taste' of the perfect classroom. What will you teach your students in order to achieve what want your classroom to be like?