Selective Edits Part 2

In this second part on selection, I take some of the techniques we used in part 1 and apply them to this sunset picture. I want to darken the top part of the sky above the clouds (selective). I start off by showing the common beginner mistake, and then show how to do a more sophisticated selection.

Sample photo using this technique:
http://www.flickr.com/photos/towert7/2625754211/