Each student participates actively in every discussion in my seminars.
All participants listen respectfully.
While it is not essential, some semblance of a circular seating arrangement helps. There are some additional implicit rules, which can be stated if the need arises. I usually suggest we try it first and clarify if we need to. If I'm particularly interested in teaching about process, I may try to restate the unspoken rules which have evolved, but usually I do not. It is frequently pertinent to have a second round, or even third round, of comments, and participants can begin or request them as they are moved.