As an operational consultant, I prefer to find out practical solutions in the case without talking too much about initiatives which couldn't be implemented in real life.
My approach:
1. Before to start the interview I want to know feedback from previous student's case interview experience to adjust my case and to cover all areas which need to be improved
2. I give feedback ad hoc every time when a student is in doubts, it helps people to adjust their approach at the beginning and not to waste time on unnecessary things
3. Be lazy and ask a question instead of just generate thousand on possible solutions, which are not applicable. In real life consultants always doing sanity checks and refer to data, but they don't generate as many hypotheses as they can, cause they don't have time for that
4. I have around 6 solid frameworks which help to crack any operational case in the real consulting interview, all of them are very easy to learn and very useful