A thought for the instructors here then....
As I think more on this subject it occurs I spent a great deal of time with my instructor ensuring the approach to the flare was spot on. It follows that if the aircraft is properly set-up and trimmed on the approach, I will cross my aim point to commence the flare everytime. Being able to land on the numbers every time, at several different fields, does not make me big-headed but it does highlight the quality of my instruction.
Specifically for the instructors, which sector of the landing cycle do you feel is most important and what are your criteria for telling the instructees to bin an approach?