My approach is to work with you in advance of the session to decide what to cover during the hour that will be most beneficial to you. With most of the candidates, however, I do a full mock interview.
If you are preparing for McKinsey, this will be a Personal Experience Interview question followed by an interviewer-led case. If you are preparing for BCG, Bain or other firms, this will be a series of regular fit interview questions followed by a candidate-led case.
After the first session, I tend to advise the candidates which areas to focus on to maximize his/her chances. In the subsequent complementary session, I tend to cover the areas that the candidate has a weakness (e.g. framework, quantitative questions, etc.)
