When a group is disruptive, if two members are goofing off, and so on, I just quietly walk over to the group's table and silently remove the top card. I have never had to take more than three cards from a group. This quiet, visual reminder really helps my students to stay on task. Give students a big round of applause when they come to the stage and, of course, a big round after. It really changes the atmosphere in the room.
Students seem more relaxed and the audience really seems to pay closer attention.
A way to improve student notebooks is to send home a parent evaluation sheet. Students spend about 15 minutes explaining the unit of study in the book with their parents, and the parents are given a rubric to evaluate the work and make comments. I was amazed to see the comments from the parents about the notebooks. It opens up communication and makes the process more accountable for the students. Parents often write a thank you for involving them.