Since the focus of the project was creating imaginative images, I wasn't worried about the background too much. I let them choose from 4 different coloring page landscapes and they colored with oil pastels-- the only rule was the colors could not be realistic-- no brown mountains or green grass! Some of them really struggled with this! The next step was the fun bit-- I filled spray bottles with dye and let them go to town. Lunch trays were essential for containing the mess, they were wiped down in between each child.
Instead of using magazines for the kids to cut, I printed images onto A3 paper. It was so much easier and faster for the kids to go through a box of great images instead of searching through magazines and struggling to cut the pages.