A system that survives to revision

The test of a note system is not how it looks in week three. It is whether you can find and use it in week thirty. That means one place per module, a consistent naming pattern, and dates on everything. Whether it is paper or an app matters far less than whether it is one place rather than four.

And plan for the notes to be summarised rather than reread. Every few weeks, condense a block onto a single page. That condensing is itself high-value revision, and by exam term the one-pagers rather than the originals are what you actually work from.