I work (ed) in several different consulting firms (e.g. Strategy&, BCG, Roland Berger) and interviewed many candidates during my tenure.
I will give inputs based on actual standards applied in the different firms (which quite similar to be honest) and also what I personally look from a candidate.
Personally, I saw a lot of candidates using a standard case book frameworks and I would suggest to avoid this trap as it will limit your ability to response when given non-standard cases (e.g. profitability/revenue/market entry) or standard case with a major twist. My goal is to help you overcome this challenges