Two Images
This is the processed version of the "branches against the sky" photo. Now if you mouseover... (and maybe encourage the mouseover with a small click, dammit)

See? That is the original, developed from the RAW image by leaving all values alone. Now, arguably the first image is too gaudy and unnatural, but seen in isolation, it is actually just as credible as the unprocessed image. As for which is more "real" - as Ansel Adams used to say, the film is the score, the print is the performance. Half the fun of photography is the performance.
So what did I do to the original image to turn it into the second one? I am not sure of every step, but my workflow nowadays always starts from this tutorial.
(God, it's been so long I can't even do a link in raw HTML!)
I don't know how to create the same effect without Photoshop, but it has to be possible, and perhaps in that discussion there are pointers. (BTW, the whole group is a very good source of info). Then I must have done a little color balancing, sharpening and adjuested curves and levels. More complex images require adding layers and then acting on their masks to cancel out the effect or paint it it.
In the second photo the advantages of popping out colors is more clearly evident:

Here I am pretty sure that making colors pop in LAB was just the first step. I must have intervened heavily both in color balance, levels, and probably contrast.
And here is the Photoshop File for this image.
Unfortunately when you go from LAB to RGB you have to flatten the image, so that the modifications I made before changing the mode are lost. However...
Starting from the lower layer, I corrected the colors both in the highlights and midtones, taking the yellow cast from the highlights and pushing the blues in the midtones, as well as correcting the greeenish tint of the shadows with a little cyan and magenta.
(My uncle used to say that the general rule for a crowd pleaser when it's a question of color photography you can't go wrong with pushing up red and yellow - but, yes, it's a general rule and not a hard and fast one.)
Both the levels layers are used to darken the image, but in two steps; the first darkens the whole image, in the second the layer mask (the little white rectangle close to the layer thumbnail) has been painted over with the brush tool. In the mask the brush tool has two effect - the black one erased the effect of the mask, the white restores it. In this case only the lighter areas have been left to be darkened.
The brighteness contrast layer does what it says - it was used to increase contrast. Not a huge effect, but every little helps.







