Trouble is, the title of this thread attempts to provoke a response that inevitably splits into at least two camps.
For a start, I wouldn't pay much attention to anybody who is a photography teacher, regardless of how brilliant they may have been thought to have been in their youth. If you're that bloody good, then you work at the job until you retire or are retired. Period. Teaching is for when you can get nothing better to do.
The above is simply what I believe; I'm sure the vast majority of people will disagree, and that's perfectly okay with me.
Belief, self-belief, can easily be said to be what governs the 'planning' or otherwise, of a shoot, depending, of course, on the shoot. I have recently watched again a David Bailey video where he is asked exactly that question: how much pre-planning do you do for a portrait? His response was to the effect that if he pre-planned anything in that way, he'd just tell somebody else to shoot it for him. It's off the cuff: a reaction to the person in front of him at the time. And it was always exactly the same thing in my own case: reaction to a smile, to a frown, or even to a moment of embarrassment. You don't plan this shit: it happens, and if not, then you are in the wrong job.
What we need here, in this discussion, is input from Cooter, who seems to have given up on this crowd of technicians without soul or imagination. Come back - you are still the best live actor on the set!
Just doing what stamper does is a perfectly normal and honest approach to being a photographer of the moment, passing, decisive or otherwise. Why create mental chains for yourself, unless, of course, there is a specific thing you want/have to seek out, when it becomes an entirely different conversation.
Heysoos, use your mind, your eyes, react to what you see, and if you can see nothing, buy a red top, a can of beer and book your a bench in the park.
Rob
