Since the MOCA exam is a subset of the Written exam, the best way currently to specifically prepare for it is to command MOCA Blue and then come to a Written Board review course. 

The MOCA course is a question-answer testing course which runs from Thursday to Sunday in several cities and over several dates.  The schedule is below.  The exam is simulated by having participants take a series of tests, each lasting about 1.5-2 hours.  Following this, Dr. Jensen reviews the correct answer to each question tested as well as relevant information pertinent to each question.  To facilitate this review, each participant is given a syllabus of correct answer choices, the rationale for each answer, and accompanying relevant material pertinent to each question covered (since the exact question is unlikely to be tested, but the topic is highly likely to be tested).  Ethical and copyright considerations preclude distributing the questions used, but the syllabus provides a complete guide as to the information one needs to know about important topics likely to be tested.  This format has been utilized for over a decade by several thousand and is proven to be effective, efficient, and efficacious.