What you need: Looseleaf paper, pencil, eraser
Risk level: Medium
This method is not very technical at all, but it was too good to leave out. When writing your notes, place a piece of paper beneath it and write as hard as you can so each letter is imprinted into the next page. When you start your exam, take a pencil and lightly shade over the text. You should be able to see the notes. When finished, erase the page.