Making lists on a notepad, computer, and/or smartphone will help improve time management and your efficiency.
Personally, I have really bad memory. I would always want to do so many things and I thought that I could manage it all, but all my ambitions started to fall apart. Why? Because I did not plan how I was going to spend my time on all these different activities, I was not able to achieve all my goals.
Now, every day after I come home from school, on my calendar, I write a list of the goals I want to achieve, when I want to achieve that goal, and how much time I will spend each day/week working towards achieving that goal.
Now I am a very successful student in high school and I've won many awards for having high grades and good behavior.