Hi John,
This is a rather beautiful little photo although for the moment it does need a little work.
First up, the horizon is not level and that isn't doing the image any favours. Before we fix that you need to eliminate some of that boring blue sky. The simplest way to do this is to duplicate the image layer (Layer>Duplicate Layer) and then use a clever piece of software called the Content-Aware Scale tool that you will find in the Edit menu of Photoshop CS5. All you have to do with Content-Aware Scale tool is activate it, then drag the top handles of the image downwards a little; the computer looks for the largest area of open space and then compacts it a little, while maintaining the scale and proportions of other elements in the picture. Now to straighten the horizon line… the simplest way to do this is to do a conventional crop.
The second problem that I have with this picture is the darkness in that the central area; we know there is some interesting detail there but we just do not get an opportunity to see into it.
There are three or four different ways that you can resolve this but one of the simplest options is to use the Shadow/Highlight adjustment that you will find in the adjustments menu of Photoshop. If you go to this option and then pull the shadow slider over you will see the shadows begin to lighten up.
As another option though, you can use the Lasso tool to select the hill in the foreground, making sure that you add some feather to soften the edges and then use the Curves adjustment layer to brighten this area. This is what I have applied to the attached example.
The one thing that you will have to do to this image before you can save it as a JPEG again is simply flatten the image again (Layers>Flatten Image)
Have fun with this… I think it will look good as a hi-res print.
Image Doctor's edited version
About the image: This is a photo of the Red Cuillins at sunset, on the Island of Skye in North West Scotland. I was there on my annual trip walking in the mountains with some mates. There's a lot I like about this image: capturing the reason why these hills get their name, the diagonal lines of the hills in the foreground and the clouds, all against the symmetry of the boat near the corner of the frame. I also like the tonal distribution. But there's something (or maybe more?) thats not quite right...would really appreciate some advice. – John Newman