Tim's general rules of thumb for learning better editing:
Rule 1:
All your common edits are subtractive, that is they remove information. Even though you may talk in terms of adding clarity, adding contrast, adding saturation, etc. the tools really subtract. Look at the image above, where is the colour? (I'm guessing) you've tone mapped - removed contrast - then added contrast/saturation back in (same thing unless you can separate your colour from your luminosity?). In simple terms you dull the colour by adding grey then thin them back to whatever hue is left. (Guessing again) the added clarity has introduced a pall of soot around the rocks in the foreground and the pillars in the bay. Adding black does little for colour.
So rule 1 is do as little as possible and always shoot with the aim of doing as little as possible to achieve the result you want, that way you preserve as much of the original information as possible.
Rule 2:
Sharpness is an illusion not a fact. Everything in the photographic process dulls your image (see Rule 1) so there's no such thing as a sharp image, only ones that appear sharp. Take a look at this watercolour (yes, watercolour):
Rock Ola
Now if Ralph Goings can do that in watercolour then there must be more to sharpness than clarity sliders and unsharp masks eh?

Honestly, I've seen this Karsh image held aloft as a pinnacle of sharpness, but if you really look you'll see (even at this low res) just how little is actually in focus (clue - look at the jacket and you'll see the depth of focus clearly):
The Last Famous Picture Gallery : Photo
It's all an illusion caused by trickery and subterfuge,

I probably explained it best here in one of my old postings. Scroll down to the long winded ramble...
Autumn Spruce and Scots Pine, Black Mount
Rule 3:
Fix your White Balance before you start. Colour balance is very important especially if you're going to do big edits (which you shouldn't if you can avoid it- see Rule 1). The trouble with a slight green cast is that everything looks slightly green and therefore everything looks slightly similar. We see differences, therefore if you want to be seen be different, therefore if you want colour to be seen make sure there are different ones in your image not just shades of the same one.
Rule 4:
A little contrast in the sky does not equal a storm, especially when it's only stratus cloud with flat calm water.

