If you can teach children quickly, using very little talking, then your effectiveness teaching adults will be vastly improved. Teaching adults well is very much same in principle as teaching children, you will learn far more teaching the children, about both your own Aikido and your own life, than they will. You will learn to teach their bodies, and their bodies will then teach it to their minds in good time, far more effectively than you ever could.
Compared to adult classes, clearly there are some specifics unique to children's class. Here's what we've found:
Kid's attention span, ability to learn, and physical ability / weight:
Is different, hence, shorter attention span means a faster , more varied pace. Don't let them pause to let them think too much, and adapt tools and drills accordingly (although if the drills are good, they work as well or better for adults).
Rolls on pad drill warmup
The emphasis must be on Dynamic Movement:
Because of children's smaller size, in order to be effective, they must really be able to move, fluidly and easily. So, place strong emphasis on spacing, ma'ai, strong movement skills, strong entering/irimi skills, ki balance. The objective is for the Aikido to be effective especially against the larger person's weight. Children have full ability to move adult ukes off balance and perform effective powerful technique. Therefore, rather than being overly fussy about technique, what is most important with children is teaching a DYNAMIC aikido in which they learn to move fluidly, powerfully, eventually done at realistic speed.
In order to get the maximum result, we suggest make the teaching of backleading a requirement for belt advancement. (see the section on Backleading). In other words, if they can't teach the technique to someone else, they can't advance themselves. With backleading in place, you have at least ½ a class worth of instructor assistants
The best motivator for children is when they see other children their own age doing things that are good. In a healthy way, this subtle competition invokes their internal desire to improve.
The other thing that motivate children the most is recognition. To achieve this, provide many levels of multi-color belts with many levels, so that children are always motivated and can see their own progress (see attached picture)
Teaching Leadership, Role Models (and removing Ego)
Introduce the idea of a 'Team Captain' to your older children. Tell them they are the role models and they are responsible to help the younger children stay in order, practice safely, and become good students.
Using games/relays during the warmup phase (see chapter below), teach children about the value of competition as a motivation, and also that competition is NOT about winning at all costs.