I did this a few days ago but wasn't able to log in for some reason to post and now I can't of course remember everything I did...but what made the biggest difference was adjusting Shadow/Highlights. I also used the extract tool and made a shadow, changed the color of the boy's shirt, used the render lighting filter...if I were to make more adjustments looking at it now I'd soften the edges so the boy's picture didn't look as "cut out" as it does.