Formal transitions happen twice during a double-block period. My students have to move from one section of my extra-large classroom (3 classrooms merged into one) and move to another section for a new lesson with a new teacher. My students have two minutes to transition from session to session, and we play a variety of interesting music on the surround sound stereo system to keep it fun.
I frequently have my students play games as part of their learning sessions. Many students only want to play the games and do not think of creating a written records of the problems they are solving or notes on their learning. I ask my students to "split the difference" and go 50/50 on playing and note-taking. It's kind of a misnomer since there really is no "difference" to split, but the strategy makes it clear that my students should be splitting their time equally between playing a game and taking notes during that game.
Once a day twice during a two-week unit, students will come back from their individualized assignments and group as cohort. This gives them opportunity to take their assessments as a class as well participate in full class discussions, mentoring, study sessions, and peer to peer advisory.
My colleagues and I use a variety of hand signals in our classroom to avoid unnecessary disruptions and maintain focus and time on task. Three common hand signals: a signal to use bathroom; a signal for needing scrap paper; and a signal for asking a presenter to speak louder. We introduce all of the hand signals to students at the beginning of the year in a community-wide Town Hall Meeting.