The question was,
ader said:
... what do you do when you know something would make a great photo but when you take it it looks like the proverbial "crap"....
I was replying rather narrowly to that specific question. If you modify that to "What do you do NEXT...", I would answer, somewhat simplistically, "Move on".
Every photograph you author will NOT be a wonderful masterpiece... not *EVERY ONE*. At whatever level you are, there will be some that ARE.
As far as I know, there is no one set method, mindset, philosophy ... short cut ... that will guarantee success. There IS one way to invariably guarantee that you will NOT make a "wonderful masterpiece", and that is to stop.... not take the photograph at all.
There are (and were) *many* well-respected, "great" photographers. Each seemed to share one distinguishing trait - the were ALL different... and they all regarded their differences as sacred to their art. Ansel Adams did NOT "see" things in the same light as did Edward Weston. Horst was markedly different in viewpoint than Irving Penn. I agitate in a different manner than Aggie does...
What to do... NEXT???
Keep at it. One of the hardest lessons I've had to learn is that the body of knowledge/skills you will gain from experience (and I really don't know of another way - experience can be directed by teachers) WILL improve YOU. The more you do, the more instances there will be of "wonderful work".
Stillman Clarke - from an article in Camera and Darkroom - said it ... he spilled the great "Rosetta Stone" secret of photography. Some of us had to endure the trials and tribulations, to struggle up the mountain, to finally obtain "The Great Secret" - which he revealed - and I am about to relay to all here... Ready? ...
"Shoot, and shoot... and shoot some more. It will come. It *WILL*."