It is always difficult and depressing to be asked to work with cell phone pictures. They have come a long way, but they are still no match for a DSLR. Recently, I was asked to take pictures of a friend for her and her twin sister's birthday coming up. I was only able to photograph her. Her twin sister sent me pictures taken on an iPhone in Georgia. My task was to combine these images with the ones I took (on my Canon 6D). I was very sad when I received these because I didn't think it would be possible to mix such low quality with high quality. Despite my fears, I got to work making the iPhone pictures look as much like a DSLR as I could. I matched the colors to the ones I took and added a gradient blur for a depth of field look.
I am glad I stuck with it because I am proud of the work I was able to do on these images.