The one over-riding thing I get from this thread is that EDUCATION is what is needed here... not arbitrary 'rules' that essentially achieve nothing (no leaning on the ground, 3000', 5000' et al) and may even be DAMAGING your engine -they're certainly distorting your fuel-burn figures. Students deserve the respect of being taught the correct way to handle their engines from the ab initio stage, and if, as an instructor you don't know or are not sure then it is YOUR RESPONSIBILITY to train yourself first, then pass that knowledge on to your students.