the buddy box is great for teaching take offs and landings... these are the situations were the instructor might need full control immediatly.

one thing that an instructor on the box should realize is that you dont HAVE to take control immediatly. if the student gets in trouble and is high enough, let him try to recover... I have seen instructors take control as soon as the student gets a bit off course or a bit too banked... then the student, after soloing, gets in trouble on their own and cant get out of it.

I also like to get students doing basic aerobatics when they start to get the hang of the pattern.. something like loops and rolls.. this way they get comfortable seeing the plane in unusuall attitudes.

I feel that you should start training recovery techiques as soon as the student is able to learn them, that way when the studend is in trouble they know off the bat what to do.