To-Do Lists are particularly useful when you have a small number of tasks that you need to complete. However, they can become cumbersome when you have too many items on them, or when you need to progress multiple projects. At this stage, it’s worth starting to use Action Programs, which are designed to manage more complex situations reliably.
Recently, The Art of Manliness provided an historical look at checklists, along with a detailed primer in deciding which lists will work for you, culled from the excellent, The Checklist Manifesto. You can implement the same routine in your daily work to help give you a greater shot at success.
But in you’re in an operational role, or if tasks are large or dependent on too many other people, then it may be better to focus on a longer-term checklist, and "chip away" at it day-by-day. Many people find it helpful to spend, say, 10 minutes at the end of the day, organizing tasks on their list for the next day.
By keeping such a checklist, you make sure that your tasks are written down all in one place so you do not forget anything important. And by prioritizing tasks, you plan the order in which you’ll do them, so that you can tell what needs your immediate attention, and what you can leave until later.