What's wrong with the "classic" approach, which has been working for more than 100 years?
- Identify the topics you don't know good enough yet.
- Write them on a small piece of paper you assume your teacher won't notice when sitting behind his desk.
- After writing everything down thoroughly and in detail you notice you don't need the cheat sheet any more.
Even if 3. doesn't happen for some reason: The teacher's desk is
very far away during COVID-19.