In my classroom I have created a culture where students always know what is expected of them. I have different procedures for kids standing up, lining up and attention getter. I have a job system so students know all of their responsibilities. I drew and painted them myself.
In this third group of 8.5 X 11 posters of hand signal posters for when students want a drink of water, need to sharpen a pencil, need a tissue, go to the restroom, or need to throw something away. With these signals I can easily give a not or just say yes and not have to waste classroom instruction time.