Calendars
Using a calendar can help you organize your schedule and keep track of all of your events.
An example of a free calendar that is accessible to everyone is Google Calendar.
To-Do Lists
Write to-do lists in order of importance/due date or in order of difficulty.
An example of a free To-Do List that is acessible to everyone is Google Tasks.
Labels
Use labels to keep track of notebooks/binders, and revisit them regularly to ensure that there are no loose or incorrectly placed papers.
You could get them from Muji, Staples, Walmart, and other stationary stores!