Set the seating for the work, not the friendships

Seating tends to be set once in September, by history and by who asked to sit where, and then every kind of lesson happens inside it. But the layout is a standing instruction: clusters invite talk whether or not talk is wanted, rows suppress it whether or not it's needed. Choose the arrangement per kind of work, and behaviour management gets quietly easier because the room stops contradicting the task.

In practice

• Default to the layout that matches your most common lesson type, and make the switch to the other layout a rehearsed routine (see "Rehearse transitions"), not a furniture negotiation.
• You own the plan, and you say why: "You sit where you learn best, and I decide that from the data I see." Review it every few weeks so it never reads as punishment.
• Wherever the plan puts people, keep your sightlines (see "Stand where you can see every face"): no seat should be invisible from your usual positions.