Hence in haste!

Banishment! be merciful, say 'death;'
For exile hath more terror in his look,
Much more than death.

One of the best management techniques I've had the opportunity to use is what I call "filtering." It's useful when we are going to be conferencing or working in groups or discussing... anything that calls for the students to have work completed in preparation.

Before class I call a couple of other teachers and ask if I can send a few students to their rooms. Sometimes I get some "no" replies, and that's okay. I have enough people who'll help me that I try to "spread the joy" as much as possible.

I collect the work and review it very briefly for completion and evidence of comprehension - with written reflections it's pretty easy to spot BS straight off. Students who did not complete their work are given the "opportunity" to finish it - on their own, silently, elsewhere, cut off from their peers. (As much as possible, I try to send my seniors to freshman classes. I am the Meanest Teacher EVAR.)

During our Frankenstein unit, we had four class periods set aside for small-group discussion. On the first of those days, I sent out probably twenty students (out of 32) and had to re-arrange the groups because they weren't groups anymore... I was lucky if I had a matched set in any of 'em.

On the day of the last meeting, I only sent out four students.

Image thanks to http://goingconcern.com/