In LR4 I applied brushstrokes as follows:
To the sky: Temp -21, exp -.6, contrast +55, shadows -50
To the horse & rider: Exp +.1, shadows +25, saturation +20, sharpness +30, noise +50.
Globally, temp 5200, tint +2, clarity/vibrance/saturation +5, sharpening +30, NR luminance +20, enable lens correction.
The sky/tree interface looks a little rough because I used the auto-mask for the sake of speed.
Jim - Long time listener, first time caller.