I did two pictures in reponse to Pier's review piece koinup.com/pier/work/52005/ to see what I could come up with using windlight and I will confess I didn't find it that easy.

This version works if you don't have access to anything but the most basic post prod tools. I set the windlight sky settings to Gelatto and then played with the clouds and colours till I got the effect I wanted. In this version I placed the sun low behind the mountain...thus casting shadow on the foreground and meaning not as much definition was needed, although I did increase contract post prod and do a little blurring of edges. Water was set to glassy.

 
Credits
Photo - Cala Rossini