Here’s a link to a collection of UK landscape photographs that have been selected as the best of the year: http://www.telegraph.co.uk/news/picturegalleries/uknews/10127144/Landscape-photographer-of-the-year.html?frame=2593201
Study them carefully! I think you should be able to pick up lots of signs of Photoshop and High Dynamic Range (HDR) imagery!
