I shall share my experience with note making and revision. I entirely relied on digital notes. My notes were created in Evernote ( I had subscribed to the premium plan). This meant that I could access my notes anywhere for all eternity. Let me list down the strategy that I followed.
- Digitisation: All my class notes were digitised. I bought a scanner for this and thereafter would use only A4 sheets for writing notes. Once I was done preparing notes on a topic, I would simply scan these papers and create a note for it.
- Proper indexing: This is very important. Unless and otherwise digital notes are properly indexed and tagged, you are screwed. I evolved a system of my own for all of this, which meant I could navigate easily to any note of mine in two-three clicks. Have a look at the index.

- Right Product: It is very important to choose the right product to prepare notes and stick with it. You can’t follow a strategy where you keep some materials in folders, some in text files, some in evernote, some in one note etc. It has to be harmonious.
- Try to make the note preparation interesting: To be able to better remember details, I would include pictures of interesting things. This helped me a lot. For example, here is a question that was asked in 2015 prelims paper about the Dhauli elephant. I could immediately remember this exact image from my notes. My entire art & culture preparation was very interesting because of this.

- Repository: I created a repository of question papers and other details that I needed and hence never even had to rely on google for previous years question papers. I went ahead and categorised them according to the syllabus and this made it much more easier to revise.

- I created a Factbook for revision before the prelims so that I can quickly revise all the important points that need to be remembered in just under a day without going through all the books.

- I also made use of mindmaps for topics that were deemed fit for that

The most important thing in all of this was that I enjoyed the entire process. It was almost like my own pet project. It helped me a lot in remembering and revising things. It also gave a sense of achievement when these things were properly organised and indexed. It was almost like the execution of a well documented project. The Engineer in me was fully awake to the challenge.