I use the Closing Bell strategy to bring my students back together as a community at the end of each class to check for understanding, debrief the class, give "grows and glows," and/or preview what we will be doing the following day. Building in this type of closing at the end of class is especially important in a blended classroom when students are spending so much time working independently or in groups.
Daily common planning has been an essential part of the transition from a traditional to a blended classroom. In my model, I essentially co-teach with six other teachers in the large classroom, so we have valued the daily meeting very much for the first three years. We are considering scaling back on the meetings in the future. We use this time to plan logistics, review student data and lesson study.
At the beginning of each Independent Learning Zone class session, I do a quick review of Independent Learning Zone Expectations. This strategy encourages the whole class to come together as a community with common expectations in mind before students begin working independently for the remainder of the class.
During Live Investigation and Task sessions (both teacher-led), I often use a whole group discussion format just like a traditional classroom. Blended or not, there is no substitute for discussion.