Don’t leave your To-do list empty, regardless of how full your calendar is. Even if you schedule all the tasks that you are supposed to take care of this week in your calendar, do not leave your To-do list empty. It’s okay if the same item is found in both locations (both in your calendar and your To-do list). Even if your calendar contains all the information and details that are essential to get everything you are supposed to handle this day, week, month, or several months, done without the necessity of reviewing any explanation elsewhere to get the idea of what’s going on, your To-do list should act as a separate source that also contains all the information and details about everything that you are supposed to deal with in the current day, week, month, or several months.