Start by organising yourself. Gather all the information you need for the test you're taking, then arrange it in a way that makes sense to you. For instance, you might want to list down all topics you need to revise in decreasing order of difficulty. Use mnemonic devices (a system such as a pattern of letters, ideas, or associations which assists in remembering something) to help you remember information that you might otherwise forget, but avoid memorising everything because it is more difficult to recall a list of unconnected facts than it is to recall a network of connected ideas.