This past semester I used a Markdown editor and .md files for most textual notes. It's not difficult to format the text or insert media, plus you can very easil

This past semester I used a Markdown editor and .md files for most textual notes. It's not difficult to format the text or insert media, plus you can very easily "back them up" using a Git repo or some other versioning system. For example I had a private Github repo for those notes and I could view them whenever I needed to pretty much. I prefer to stick to handwriting when it comes to math classes purely for the flexibility of being able to sketch/scratch out stuff with relative ease.