[mGGAequitas]

build 3 raxes -> expand ->build 3 raxes -> expand -> etc. etc.

you should just be teaching to macro,and to improve mechanics.
In my opinion its not worthwhile learning one build and blindly doing it every single game, because if your mechanics and macro is bad you will lose, even if what you are doing hard counters the opponents build, just they macro better. and also because they will get to a point where the build just does not work regardless of their mechanics, macro, micro. Teach your 'trainee' to react to what they scout instead of blindly doing builds.