I have a written weekly timetable for dd and prompt her to check it twice a day (before and after school), that includes things like music practice, homework and PE kit days. For ad hoc tasks like putting washing away i ask at the time i want it done, and give her a time limit eg 'within an hour' because she doesn't always want to out her book down immediately.
We don't get any homework thay goes on longer than a week, so dd doesn't need to plan that herself, but if she did then i think i would break it down into chunks for her, and agree the night of the week that the project work would be done on.
To be fair, dd doesn't have a huge amount of unstructured time at home between my working hours and her weekend activities, so we fo have to be reasonably regimented