It is better to have a to-do list than not having anything written down to do and simply using our brain to store the tasks that we are supposed to do, but there is something even better and more effective than that. It is scheduling your tasks rather than simply using a general list that can sometimes turn out to be overwhelming and an insurmountable endeavor.
We get very excited to have a very long list of things that we think we can do in a single day, but a few days are enough to pass until we get aware that we are not able to finish all those long lists of to do lists. There does not seem any point in the foreseeable future when you will finally be able to finish the whole list, because you have such a long list of tasks to do. What you are not taking into consideration is the fact that you have a limited time in your day and not allocating a time period that you think will take each task on your list will make you less effective.
Aiming to finish off everything that you have on your list simply because you were able to prepare that list is not rational and even possible. Instead, try to have tasks and set a time slot in your calendar when you plan to finish them. It does not mean that you will always follow the initial planning and schedule, but it is a solid point of starting your day on the right foot.
Scheduling is likely to make you more productive, because you are able to have a real picture of your day and how it can realistically can be filled up with tasks that are planned to get done. Do not forget: Things take longer that you might expect.