In General, It's Best to Avoid Generalizations
As a photographer, you sometimes find yourself encountering a situation unlike any you have before. Other times, you're on more comfortable footing, photographing a subject you're already familiar with. Even when you feel you do know how to shoot a subject though, it's generally best not to generalize, if you'll pardon the awkwardness of my phasing.
When you look at a scene you're interested in photographing, one obvious task at hand is to decide how to go about it. Clearly, the final act of pressing the shutter release button will be part of the answer. But the creative challenge of photography is to work out where to be when you press that button, how you want the image you take from there to look, and how to go about making that image happen. Where to start, and how to proceed are more important than the final destination of pressing that button to snap the shutter.
Often, there's only a limited amount of time available to figure out what you want to do. Whether it's because the light is changing quickly or because your subject is about to run away and hide, the net effect on your decision making process is the same. You're under pressure not only to make good choices, but to make them quickly.
With all those details to work out, it's convenient to base at least some of your choices on situations you've faced before. If you like the way your images came out the last time you had to photograph something similar to what you now face, one easy solution to the task at hand is to do more or less the same thing as last time. If you look at making the necessary choices as an exam or test, it seems reasonable to assume that you're bound to do better if you already know some of the answers.
But if you always make the same choices given similar situations, it should also make sense that there's a reasonable likelihood you'll end up with images that look at least somewhat similar each time. Generalizing your situation will tend to contribute to producing generalized outcomes. Only by treating each situation as new can you avoid the trap of treating them as the same.
The truth is, it's not just in photography that people do this either. We all do it at least occasionally in everyday life. When done to excess, it's labeled as prejudice; you "pre judge" the situation. When done less overtly though, it serves as a necessary means of getting through the day. If you had to treat everything you encountered as if for the first time, it would be hard to make a cup of coffee in the morning, drive a car, or even read a thought provoking article. Such as this one.
But when we generalize as part of a creative pursuit such as photography, we diminish our opportunities to be creative. Repeating choices you've made in the past is a very good definition of not being creative in the present. After all, in order to be creative, you have to create.
Even in photography this advice doesn't pertain to everything of course. The buttons and knobs on my camera only work a particular way (barring changes to their function enabled by adjustments to other buttons, knobs or settings elsewhere on that camera). I may be able to swap the aperture control dial with the one that controls the shutter speed, but a halving or doubling of either will still affect the exposure by one stop. And opening the aperture up to a wider setting will still result in less depth of field regardless of which knob did it, just as shooting with a sufficiently slow shutter speed will cause moving objects to render as blurred, all else remaining the same. The optics of light can't be ignored any more than the speed of light could be. The more you know about how light woks the better, and the word photography literally means "painting with light." The more you know about how your camera works the better, or you'd scarcely be able to use it effectively no matter what you may decide to do or avoid deciding by generalizing as the same as last time.
The dividing line between what to work at knowing well and what you're better off doing your best to see afresh each time is pretty clear cut too. When I take a picture, my camera better work the same as it did last time. I count on that. If my camera didn't do that I should take it back for repair or get a new one. But to the extent that I compose every picture of a mountain stream the same way, I likely won't ever go beyond that particular way. I cease to be creative. Photography is both a science and an art, and it is this latter realm that I'm talking about here: the artistic, creative part.
So if you find yourself photographing a mountain steam, don't look at it as being the same as the last steam you saw, even if the last one was in fact this same stream yesterday. Figure out what you can do with it by actually looking at it rather than remembering the previous day's encounter. And then rely on your years of experience and understanding of how cameras and light work to capture the image you've come up with as best you can.
You won't always have the luxury of making every creative decision in real time. A whole host of factors could limit the time you have to work on any one image. Generalizing some choices can mean more time to focus on other choices, and wisely using your time only makes good sense. Learning this is another thing you don't want to figure out from scratch each time. It really comes down to the creative act of visualizing what you want to do, not so much how to do so mechanically. It's the creative side of photography we're talking about, not the technical side.
Among many memorable quotes, Mark Twain is famous for his edict that "All generalizations are false, including this one." The man did have a way with words. Acknowledging the truthfulness of his observation here, it's hard to discuss the subject I've been talking about this week but hopefully you get my point.
Generalizing your creative outlook isn't always a bad thing. Only generally so.
Worth a passing thought at least.