this is cool, but youve made a critical error with your details in the shadows.... take your smudge tool and push in the shadows on all the parts where the sand ripples so that the shadow flows with the natural ripple-like texture of the sand... also with the sun's intensity like that the shadows wont blur like that... blurred shadows are a result of the intensity of ambient light (or in otherwords, lesser light being reflected off other surfaces) because of this, there would be almost no blurring in the shadow at all.... this might work a little better had this been a dim street light or something, but not the sun! just thought you should know... im a detail freak myself so this kinda stood out for me.
if i use ??