Split the Difference
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.
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 use this strategy to activate my students' interest and prior knowledge on a topic. This gives me a good starting point on the curated video and reading list for the independent station. It also gives my students a visual representation of the range of interests in the class. In my opinion, using the interests of my students to guide instruction is the core of a student-centered classroom.
Positioning is a strategy I use, especially at the beginning of the school year, to ensure that my students know where they should go, what they will do at each station, and how much time they will spend at each station. Positioning occurs after I welcome the class (please see the "Opening Bell" strategy video) and before they begin rotating. I typically project the group assignment page from our class website onto the smart board and do a few quick checks for understanding before I let students go to their stations.