Organize your tasks with a free online to-do list that saves everything in your browser: create multiple lists for different areas of your life (school, work, personal, chores), check off tasks as you go, and clear completed tasks whenever you like. No sign-up needed.
Having more than one list helps you focus: while studying you don't want to be distracted by your personal list, and while shopping you don't want to think about school work. Write tasks down as soon as you think of them, then revise your lists daily to stay realistic about what you can get done.