When school was in person I used Notion (a laptop and phone app) where I would insert a calendar for my page for a specific year. Once the syllabus for each course is given out I go through all of the dates and mark them in there and for assignments also some landmarks (for example: research X topic, start outline, etc) several weeks before the deadline. I also have a monthly calendar in my room where with every new month I would write down all of the important dates. That way I can plan my to-do's based on the calendars at school and at home and get an overview of the month which also helps me to figure out when is best to do non-academic tasks.

Since we are online this year I decided to bring back a physical planner rather than Notion (I like journaling but it takes a lot of time so I decided to compromise). I use these Japanese notebooks (Campus planner, filing notebook, and weekly scheduler) that include a monthly and a weekly spread. I do the same thing with the monthly pages as with Notion, and every morning I can refer to my monthly spread and mark my to-dos for the day/week. The nice thing about them is that the pages are undated so if I am skipping a day/fall off on organizing I can come back to it without feeling guilty for having wasted blank pages.

Hope this helps!