I think you're being a bit harsh on yourself here. The thing that strikes me most is a problem with the framing - I'd have liked to see a bit more of that tree across the top of the picture, even if you'd lost a bit of the rocks at the bottom.
You could also try adjusting the levels a bit to increase contrast and possibly add a reddish tint to simulate a time closer to sunset.
1.) Load Image, convert to 16-bit
2.) Levels: Adjust white point
3.)Curves: boost red, reduce blue in shadows (greatly) but no too much in midtones, highlights & overall increase contrast
4.) Sharpen slightly
5.) Shadow/highlight tool:
a.) Shadow: amount = 20%, Tonal width = +20%
b.) Highlight: amount = 7%, tonal Width = +70%
6.) Hue/saturation: increase saturation slightly
7.) Final adjust curves
8.) Convert back to 8-bit
Finished
Note that the shadow/highlight tool is specific to Photoshop CS, but I know there are stand-alone tools out htere that do the same thing, and you can also do a contrast mask technique manually to achieve similar effect.
One of the problems you will encounter with this shot is there seems to be a very heavy blue tint in the shadows, so once you bring up the brightness in the deep shadows at the bottom, you will see the need to adjust the blue channel pretty severely to compensate. I used curves, it may be very difficult to do without curves.
BTW, all DPC-legal.
