This might seem elementary.but I love the quiet spray idea! Very cool teacher ideas on this site. Quiet spray has nothing in the bottle but air. This may be the smartest classroom management tool I have ever seen.
Make and put on the door - Teach-A-Roo: Ticket Out the Door! This can be used as an exit ticket. You could put critical thinking or math on the door. This gives the students something to do when waiting at the door.
Students created dream jars from Roald Dahl's story "The BFG." This teacher has created a bookshelf bulletin board display, along with a large drawing of the BFG, to showcase her students' dream jar projects.
Class Dojo is a great classroom management website and app. Use these free posters to focus your students on a particular goal for the day or week. The goal can be for the class as a whole or for individual students.