Top
Original image

Center
Clone away the hot spots around perimeter of image.
PWL layer (softlight blending mode) to add sparkle and contrast to the waterfall.
PWL to darken vignette and foreground pool.

Bottom
Possibly add an artistic effect: Buzz Simplifier or one of Photoshop filters.
Add to a duplicate layer so that the effect can be adjusted using layer opacity.

forum discussion: http://forums.dpreview.com/forums/read.asp?forum=1006&message=27408592
original image by Eduardo