1) 123 eyes on me, 12 eyes on you. and other attention getters
2) Ring a bell: Great for getting attention with level 2 and 3 activities
3) Apps: Great for overall monitoring
4) Quiet Critters: Great for monitoring level 0 and 1 activities. Give a critter to the students working quietly and monitoring the behavior you want to see.
5) Silent Spray: Water with a drop of lavender essential oil. Spray around the room before starting a level 0 activity.
3) Bell work upon entry and transition routines: Make sure your students have something to do the minute they enter the classroom before the start of the days first activity. This will ensure that everyone knows what to do when they come in and during transitions.
The most important part is being consistent with your students. Always make sure when introducing an activity to point out what noise level is expected, quickly model it, and then monitor it. Make corrections quickly and privately as much as possible. You can say things like “I see two people that still need their eyes on me,”
I hope this post helps you brainstorm ideas you will want to implement in your classroom. Praising and noticing good behavior is by far the best way.