My kids are annoying me with their terrible organization habits. Any tips on getting 6th graders to get their lives together?

I have modeled 3,593,219 times how to organize one's desk. I have required binders with color coded folders for each subject, and bought them myself for kids who didn't bring one. We take 5 minutes every day to write homework in our agendas and organize our folders.
Somehow, I still see loose papers in desks DAILY. I used to give PBIS rewards for clean desks. Maybe I need to start that again. What else can I do?
They're so bad. I'm tempted to post pictures here.