Case Prep 3: case books
Attached are the case books you can use to practice your casing skills. These cases tend to be geared towards BCG, Mckinsey, Bain, and Deloitte interviews. However, if you can perform well on these, you will be able to ace any interview you have with the Big 4 or other boutique consulting companies.
My personal favorites are the Darden and Wharton casebooks - Jan Joho