Keep in mind the time (interval) you study and the level of difficulty of topic/subject.
1. A good study plan looks like a bell. Your time and level of subject matter difficulty should gradually increase. As you get closer to the final exam, you should decrease the time interval (because you should know it) and level of difficulty (because you are now reviewing the information).
2. Study the most difficult information with enough time for you to ask professionals for clarification.