Answer:
Cleaning - A clean environment can set student's mind at ease, and make them feel more comfortable at their surroundings.
Organized Desk and Lesson plan - If your desk is organized people might follow in your example and have their things organized as well, an organized plan can help you, the teacher, know what you have to do, and what is next, and it helps the students keep more attention cause you don't need to stop and regain what you had to do.
Nice smelling environment - Usually when rooms/environment smells nice, students can relax more, and not have to deal with putrid smells.
Set up a warm up - It could be from a simple problem, to just a fun crossword puzzle of your subject, this will help prepare students for the lessons ahead, wake up their minds a little bit.
Hope this helped.