The more prompt and specific we can be with our feedback, the more opportunities our students have to focus their efforts appropriately. In addition to being prompt and specific, responses are most useful when students can actively use the feedback in some way. If they encounter an offensive object, they will try to bury it. Humans engage in something similar. We need to create an incentive for students to process the feedback we provide.
Good practice emphasizes time on task.
All else being equal, more time on task leads to greater learning. Clearly, students need to learn to allocate their time effectively, and perhaps as faculty we can help with that. Beyond that, though, we can make sure that we use the time we have with our students efficiently, and that the work we ask them to do outside of class is indeed worth their time. Assigning work, of course, is only half of the process. We need to think about ways in which we can encourage students to do the work and do it with intellectual rigor and serious intent.