what i usually (try to) do with our youth earnabike, if they're not really getting the gist of shifting, is head to a local short, steep hill. start them out at the bottom of the hill, with half the group in the fast/hard gears, and the other half in the slow/easy gears. now, have them race in an orderly fashion up the short hill. it can even be as short as 50 feet, so long as that person in the low gears is gonna win the race. now. have them switch gears/bikes, so that the hard pedaller can see what it's like in an easy gear, vice versa.

 the same lesson could be taught at the top of a hill, showing how the fast/hard gears do have a place, while the slow/easy ones suddenly are next to useless.

we have our own version of footdown, which is no-contact. just have them ride in a circle without touching down, and the circle gets smaller and smaller, so they have to ride slower and balance more.

we also hype up our "slow race" to the kids, from early on. it's basically footdown played in a parking lot or field, with a starting point and an ending point, and the goal is to go as slowly as possible without putting a foot down. you also can't turn around and ride backwards, touch your opponents, or just wait to start until everyone else has. once the teacher says "go", you gotta go. this is a fun one, since something a lot of the kids want to do early on as soon as they get their bikes is race. this way, we can let them race, and don't have to worry about them crashing at 20 mph.

the slow race and foot down are also fun if you've got a shop member or teacher or guest or someone who can trackstand, or even ride backwards, then it's fun to watch the kids protest when their competitor goes backwards without turning around.