I passed both the written and the oral on the first try. Master the game and you pass. I've prepared several persons for the oral exam, and they have all passed. The best thing you can do is emphasize the point that clinical experience doesn't help much at all in passing the exam.
Applicants are better prepared if they have some idea of the types of questions to expect.
But it really comes down to being able to answer, concisely but thoroughly, any questions from any of the domain areas. That's fair play. Just remember it's all a game. It's an open question whether the ability to master the game relates to any skills of a psychologist. The board has delineated the several domains of knowledge relating to the general practice of psychology, and the exam tests those domains.