The tips begin at a different place in each module. The advice moves along with the stages of the course.
The difficulty for some MCAT questions isn't scientific understanding. Many questions are actually tests of focus and attention. Be careful to convert to S.I. units. Read the question stem carefully. Read all the answer choices. No statement looks as much like a given proposition as something saying the exact opposite. Learn to do a quick final check before committing to the answer. The easier the question, the more important this last step can be.