My 8th grade students have created photo collages or joiners in our Digital Art Lab. They have learned about Photoshop and its many tools and shortcuts. Students took nine photos of a person, place, or thing. They had about 15 minutes to do so during class. When they returned to the DAL they placed the images into Photoshop and worked with layers to organize and connect their images to one another.
Jing, a screencasting app, helped me to create custom videos detailing how to use Photoshop.