It is a good idea to have each topic in a different colour, allowing better organisation and ease of studying. You can cut them out of paper or an empty cereal box. You can divide each subject or topic by putting holes in a corner and connecting the cards to a key ring, piece of string etc.
When you start writing out your notes on the cards put main points not entire chapters because you won't need that much to pass, the flahcards serve just as a reminder or memory jogger. On one side of the card put a question or syllabus point, on the other a few main points that will eventually stick in your mind after going over and over them. Once these points are memorised you can think of sub-points that may go under each point, creating the body of an essay or report. Write these sub-points out on a separate piece of paper or other flashcards to go over and memorises.
The art of being wise is knowing what to overlookWilliam James