Wordsworth said, "To steer is heaven, to drift is hell." Great leaders don't fly by the seat of their pants. They plan ahead - in writing. The mere act of having a definitive written schedule and action plan reduces your stress. Preparing tomorrow's activities the night before doubles the peace of mind.
You might prefer not to think about the activities of tomorrow because it might keep you from falling asleep at bedtime. This is a common belief, but the opposite is true.
By organizing your schedule and a list of activities the evening before, you actually can put your mind at ease by knowing where your attention should be directed the next day. There are no lingering questions or things to remember. You know what they are because you have reviewed them. Additionally, by reviewing tomorrow's tasks sometime in the evening, your mind can actually be working on issues you face the next day - while you are sleeping.
Research by a leading expert on the positive benefits of napping suggests that rapid eye movement (REM) sleep in enhances creative problem-solving. The findings might have important implications for how sleep, specifically REM sleep, fosters the formation of associative networks in the brain.(1) Furthermore, research shows that your brain becomes very active when you sleep, and that during certain phases of sleep, your brain becomes even more active if you've just learn something new.(2) That "something new" can be the task you just reviewed that are on tap in the morning or the study material you just learned for the exam tomorrow.
Also, your list and schedule need to be on paper. Yes, that means a hard copy. It is acceptable - and even beneficial - to have it on your phone or tablet as well. But the ability to hold, write on, color, and otherwise “feel” your activities is important.
Here is more research on the matter:
When we write something down, research suggests that is far as our brain is concerned, it's as if we were doing that thing. Writing seems to act as a kind of mini-rehearsal for doing. I've written before about how visualizing doing something can trick the brain into thinking it's actually doing it, and writing something down seems to use enough of the brain to trigger this affect. Again, this leads to greater memorization, the same way that visualizing the performance of a new skill can actually improve our skill level.(3)
There is a connection between the pen and the brain. Now you know.
"Habits, like trees, are strengthened by age."
-- J. C. Ryle