Organize a big portrait session - optimizing the flow

This post is a continuation of a series about shooting portraits for a school. I described briefly in one of previous articles about the general idea. In this post I am going to describe some human-related aspects of such session and give some tips on how to make it successful for the children, school staff and the photographer. To give you some context let me just summarize the challenge:

• The session takes 3 to 4 hours
• During this time 70 to 100 children gets photographed
• Each child is photographed twice: one photo is in a full-length pose, one as a close-up (depending on the situation either upper half of or head and shoulders
• Some children want to be photographed together with their brothers or sisters, school friends, etc.
• Each group is photographed as a whole together with their mentor teacher.

In short, such a day is intense and the border between intense and chaotic is thin. But it is the responsibility of a photographer to deliver the photos, so he need to ensure that the workplace remains decent during the day and such session doesn't turn into chaos. Here's an approach I have developed over several years. I am not telling it is perfect, but it works quite well.

1. Realize that you as a photographer are the director of the whole event. So think ahead about the possible scenarios and have a plan for different cases.
2. Get in touch with school staff in advance. Ask about their schedule, try to fit the session into school's rhythm. Ask for the school schedule during the day of the session. Plan the order in which the groups will attend the session.
3. Agree in advance how the teachers and parents will assist you. It is absolutely necessary to have help of the school staff or/and the parents. For a number of reasons: first, it is legally mandatory that teachers are present during any activity of a 'stranger'. Second, they are invaluable when guiding the group of children. They simply know how to do it efficiently. Third, children, especially the younger, feel more comfortable and safe when they have a trusted adult person close to them.
4. Prepare all your gear before starting shooting. Be on a location on time, way before the planned start. Keep in mind that setting up the background, lights, test shooting cost time (in my case it takes 90 minutes, because I need to iron the background).
5. After setting everything up look around and try to visualize how the children would walk (or rather run) on and around the setup. Then protect your most important parts! Put a chair, a table, anything that would stop the most active and enthusiast children from ruining into the arranged studio. I always stay in the front of setup, in the direction of the incoming group. As soon as I see them running I make some gestures to stop them and explain quickly how they should move and where to watch out. Then I keep them (together with a teacher) out of the actual scene, letting them stay or sit around the setup.
6. Be decisive. Children get quickly excited but they get bored also very fast. So it is important to start shooting immediately - just start talking to children, ask who is going to be first (for 100% there always will be at least one), put them in the marked place on the scene, explain what you are going to do (2 photos) and shoot. One, control, two - ready. Next child. Everything should take no more than several minutes.
7. Remember, you are a director. So when individual photos are ready, start to organize group photo. Depending on a group size decide about the number of rows, who will be in front, who in back (a rule of thumb is: smaller children in the front). 
8. Once the group photo is ready guide the group out of the scene. Remember again about securing your gear and the setup.
9. Control the setup in between the groups. Is the background still ok? Are all the lights operational? Do the assistants know how it works and how to proceed?
10. Be flexible. Sometimes you need to spend a bit more time with a child; either he/she is shy or requires some more attention during posing (like children wearing glasses). In this situation communicate to a teacher or parents so they know what is going on.
11. Ask the teacher or parent in case there is some intervention required during posing. Like fixing the hairs, clothing, etc. Again, it is about building the trust. Children trust their teachers and parents, not you. I always discuss this question in advance and ask assistants for help in such cases.
12. Have a couple of jokes ready. Use them when a child or group needs to be cheered up.