[Zig]

It may seem a truism to say this perhaps but let us suggest that how one processes a shot after it is taken, determines the final image's success.
You may then justifiably add, that in actual fact it is the combination of aperture, shutter speed, composition, ISO/noise and timing that predetermines all these: that is, if you want a good image coming out the back end, then your best chance is to get the shot right at the front end first. I would even suggest that the resulting end image should be already finished before one clicks the shutter.. adding that the press of the shutter is itself a final act of commitment. In other words, the final hard image is or should be exactly the same image that one has in one's mind's eye after looking through the viewfinder.
I stress at this point that this is my own way of working: sauce for the goose may not be sauce for the gander, this I appreciate. However, I still am of the opinion that if one "sees" the final image's potential as early on in the process as possible, then one maximises one's chances of turning that mechanical capture into as close a version as possible of one's initial "inner vision". After all, was it not Michelangelo who said that each of his sculptures already resided in the block of cold marble in front of him, and that all he did was to remove everything else in order to liberate it?
That said, of course, it is clear that how one manipulates the image between its gestation and birth, can drastically alter both the final image and what one wishes to say/suggest/symbolise to one's audience...indeed, it can decide both the nature and the presence(or otherwise) of that audience.
Sometimes I work right through from shutter to pp, ensuring the final image is merely an externalisation of the one in my head; sometimes I change this during pp. The point is, having a working knowledge of both, maximises my chances of the final shot being a purposefully- crafted good'un

I'll illustrate by a simple example, showing you one shot treated in 2 sets of ways, leaving you to decide if the 2 treatments of the same image say 2 differing final things..and if they are successful in doing so:
All the images below are treatments of the one exposure. The shot was taken, handheld, late on in an extremely cold midwinter afternoon, with slightly diffuse light behind the cloud cover temporarily just about admitting a touch of weak December sun. EXIF= Canon 50mm f1.4 at f6.3, 1/40s at ISO 200.
These are the "base" shot, representative of the conversion of the Raw file to 95MB tiff(16bit/channel, RGB).
Note the exposure favouring the sky: I have already decided to dodge in the highlights of the foreground locally later on, aiming by the time I press the shutter to have all prerequisites covered: chosen depth of field, focal plane(area in focus), point of focus, composition, retention of sky, foreground and main subject detail. Had I exposed more "correctly", some sky texture and several patches of white frost would have been "blown".
Photographers with digital savvy could advise me here to expose for highlights, given that the sensor will retain more detail in the highlights than in the shadows. True..but yet I am familar with the dynamic range and texture(noise: albeit very "emulsion-like" on the 1Ds MkII) of my sensor; my low-contrast conversion will be fine given what I already intend to do later.



Note the effect of 2 differing parameters of white balance: there is a variation in colour temperature of about 1000 degrees: the first is "warmer", the second cooler. You might decide the first is less "pure", with more of a colour caste: indeed, in filtration terms it adds about what an 81C warm-up filter would. However, though the second image is more "realistic", the amount of blues will cause me problems later on if I dodge and burn..and I had already made the decision to do both whilst framing the shot: the blues would darken considerably with burning..whilst any golden hue from the first image will become pale amber upon dodging the lighlights, thus intensifying any suggestion of late afternoon glow. If I were to proceed with the cooler-temperature conversion, the dodge/burn process will cool the flora down to the point of unattractiveness. True, the sky would be burned in more blue..but the burn tool will darken the blues anyway, also contrasting nicely with any cloud texture.

So, I proceeded with the "warmer", more attractive 1st conversion.
First I dodge: a large, soft brush; set to "highlights" with opacity slider at 3%. I have purposefully exaggerated the effect here so as to illustrate, but the idea is the same:

Notice that dodging alone can render things too pale...therefore I choose the burn tool by R-clicking on the same box as the dodge/sponge options in the tool palette. Remembering to change the dialogue to "shadows", I find a similar value of around 3% allows one to have a degree of control, keeping the speed of change manageable. See how this renders some of the foliage pleasingly silhouetted:

You can also see the added side-effects: an increase of saturation along with a shift in hue: I generally nip in and out of the saturation/hue menu, reducing as and when things become too lurid. I might also adjust overall contrast/brightness, doing such adjustments on a duplicate layer, then varying the amount of opacity before flattening the image again in the layers menu.

Finally and after much care, enough is enough: I've adjusted saturation and contrast, set my white point as any bit of 100% white snow, then added a tad of smart sharpen at whatever output size is appropriate: for the web, I adjust my longest side to 780 pixels, saving as a level 9 jpeg.

The finished product then:



As you can see, the final image is crisp and with a healthy colour; it has the boosted tones and augmented colour temperature suggesting a degree of warmth and engagement. It is a purposefully vibrant, bracing image, giving clear-ish vistas along which to draw the eye and the sense of a bejewelled winter walk and exploration in the clear air.

However, let us see how a few tweaks along the processing journey, can change the feel of the shot and suggest a different pace and quality of engagement.
Exactly the same shot and conversion to the same low-contrast tiff...but now this is the end result:



It almost looks like a time-lapse shot: the frost now appears to be snow...and newly-fallen snow at that, given the soft and fluffy texture; there is even a suggestion of a mist or of the end flurries of a silent fall of blanketing snow. Visibility now seems to have closed in, giving the scene an overlay of hidden mystery, almost inviting a different, more childlike, quality of engagement. The pace of our walk, if we were to pick our way through the seemingly fresh snow, would be slow and measured: whereas the first version of the image has a feeling of crsip vitality, this one has almost a sense of quiet hibernation.
One shot, suggesting 2 quite different ones at different times: here's how:
Firstly, the saturation is pulled way down: it's not far off monochrome.
Secondly, you can use the sepia filter in the photo filter menu, duplicating the image as another layer and merely varying the opacity to suit.
Thirdly, working on duplicate layers, you can add some gaussian blur: I also made another duplicate layer, smart-sharpening, then erasing all the detail apart from the building, thus increasing the sense of bokeh in the flora relative to the building.
Fourthly(and only if converted to 8-bit...in CS2, that is, which is what I still use), duplicate the image as another layer, then add some diffuse glow: once it's back as a layer, adjust the opacity slider of the layer to suit. Be careful not to totally whiten out the sky as you sow the illusion of reduced visibility here: you can of course use the eraser brush set to an opacity of 10% or so, thus retaining some texture in the background(your original image). Finally, you'll notice the overall contrast is lower than in the crisp, vibrant "original" above, contributing to the image's apparent softness.
The camera never lies, as they say: indeed, how can it, if it is only one collection of processes between what you see before the shot and what you see at final output. Surely, the start image in your head and the final output can be identical...it's just that the more control you have over all the pp mechanisms, the more leeway you have to develop and even transform the image as you go.