When is your zone?
Our bodies are naturally most focused, and primed for action at a certain point of the day. Until we pay attention and actually work out when this period is, we often don't know it exists. For many people it is in the first few hours of the morning. For some people, they focus best after lunch. For the unfortunate few, it's at 2am. Whenever your zone of effectiveness is, that period when you're most focused and get lots of work done, find it and use it to study and revise your most important topics.