Whirlybird. You miss a very important point in instructional technique - namely - whats right for one student is not right for another. To use your example, a weaker student may be getting a little maxed out on final approach and so the instructor says to ignore carb heat and concentrate on the approach. Another student with more capacity may be told to select cold at 500'. If the RIGHT WAY was ever invented then it would be in a book and being an instructor would simply involve reading and regurgitating the book...
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