I have watched this thread with interest. I do not have the answer.
I have tried bonuses, but then it's more work on me to tally up and keep track of the items we are bonusing. I even tried tying the group to individual bonuses thus if one person did not do something everyone lost out, still too much.
I have tried moving duties to other employees. All are good at some things, some are good at others. Sometimes you need to find the right fit. This has helped but still things do not occur.
I have been trying to get my staff to take pictures for several years. For a while I did them all. Finally I just gave up. (WARNING diverting the topic) One issue with pictures is that they have to be resized and that's a difficult task for the staff to get their heads around. Anyone have a good answer for that?