I think once you get to producing images like this, you kind of need to figure out what you like yourself. All I can advise is looking though a lot of landscape images (I got a large group of people I really like on Flickr and spent quite some time going through their images) to figure out what you like and maybe what you don't think works. And/or just shoot a lot and then go back to your shots 6 months later.
I mean I could say that some of the rocks look a bit unnaturally light, or a comment on the sky colors, but I also think it is a matter of taste and without processing it myself, I don't know if I'd prefer it different.
When I started using PS in earnest, using luminosity masks made a huge difference for me, both in speed and what I was able to do. Personally I use the mask as a selection and then brush in the effect I want (rather than just using an adjustment on the whole mask). Some people don't like them, some love them. In any case I don't see any obvious halos or anything, but for a shot like this and what I imaging the raw(s) looked like, it would be vastly quicker for me to process using luminosity masks.