I am a little late because I just ran across this fun challenge..at lease it is fun for me and will be for my students in the future. It is a great way to practice photo editing skills.
What I did to create the digital painting:
I used an original painted texture converted to a PhotoShop texture overlayed on the original photograph.
I used several blending modes on several layers to create the inner background.
I isolated the jumper with selection tools and fixed the edges to make sure he looked like they were part of the image, not just sitting on top.
I adjusted the brightness and contrast of the boy to make him clearer.
I used a doodle of shooting stars, duplicated the layer several times and fiddled with blending modes for depth.
I painted the shoes bright red on another layer adjusting the edges carefully.