When we plan for instruction, we need to choose relevant and authentic tasks. In most classes there will be students of different levels of ability, none of whom should be burdened with busy work. Structure your classroom in such a manner there is always one more thing to do. Just ensure the 'one more thing' leads the student to a deeper understanding of the current objective or prepares them to enter into an understanding of the next objective.
This should also remain true when working with teachers. If you find yourself working with pre-service or in-service teachers, ensure the artifacts they are asked to produce can be used when they return to their classroom. If the artifact cannot be used in the classroom, then why create it?
No busy work please!
Resource: Surface Area and Volume module recently produced for an online course.