A few weeks ago I finished interviewing for MBA consulting internships and wanted to capture some of my thoughts while they're still fresh. There are lots of good resources foravailable, but most of the truly great advice I received for behavioral interviews was from personal connections. Below is my overview of tips for succeeding in the process. This is meant to be thorough, and reflects my experience through 20+ interviews. That said, it is likely not exhaustive, and I welcome any additions or comments you can provide. I'll add sections or elaborate, as appropriate.
Acing the case is table stakes; lots of people will do it. Unless you show some amazing creativity, the case is unlikely to be the differentiator in a decision round. Also, in a combo fit/, the behavioral portion is usually first. If you make a good impression and develop rapport here, the interviewer is much more likely to help you during the case. If they've decided in the first 5 minutes that you seem smart, that little arithmetic error during the case may be considered a fluke rather than indicative of an underlying analytic weakness. Finally, "fit" evaluation continues through the case. Don't turn off the conversational ability and charm just because the case starts.
You should approach fit/behavioral prep with the same precision that you do case prep. Either devote some full sessions with case prep partners toor (my preference) ask each before every case, and be brutally honest with feedback.
Background/Resume Walkthrough - Dial-in a cohesive 90 second resume walkthrough that focuses on the positive motivating factors behind every transition (school to job, job to better job, most recent job to grad school). E.g. "I went to school to design cars, but after one internship I realized I liked interacting with clients directly and pursued full-time roles with a sales bent. In that role, I develop solid sales skills as well as gaining exposure to a, b, and c. I wanted to continue honing those and branch out to focus on x, y, and z. I sought a new role/promotion which provided that opportunity..." Be deliberate. Every move you made should have a reason (preferably that you initiated). Don't be negative. Never say you left because you were bored or "wanted to try something new."
Basic Questions - Why do you want to do consulting? Why this firm? Why are you a good fit? Tailor these answer for each firm and practice the hell out of them.
Desirable traits - It's not hard to figure out the questions you'll be asked. They usually take the form of "Tell me about a time when...you dealt with a difficult client/you led a team/you persuaded someone/you were a good teammate/you failed/you faced a challenging situation." Here the trick is to answer the right question. So many people get dinged because they try to fit a leadership story to the team question or a weakness story to the failure one. Ideally, you can come up with 6-8 stories that cover the 30-40 basic questions, with only slight modifications. Don't wing it. For every potential question, map out the story using the SOAR framework. Describe the Situation (10-15 seconds), Obstacle (10-15s), Action (60-75s), and Result (15-30s). Stories for these questions should be 1.5-2 minutes long and focus only on what's important.
Be specific - Even if the interviewer asks you to describe your leadership style or for you top 2 strengths, you should hear "Tell about a time when..." and answer with a real example. "I lead by doing and exhibited this when I [faced this situation][that was challenging because stuff][so I did some other stuff][and it worked out like this... and I learned this for next time].
Delivery - I said you should practice the resume walkthrough and your SOAR stories to the point of having them memorized, right? Well, don't spout them out as a canned response or let your eyes light up with that "ooh, I know the answer to this one" look. The stories should sound like they are thoughtful and come very naturally like you're telling them to a colleague at happy hour. If you don't use pretentious language in normal conversation, don't do it here. Draw the interviewer in; they should have followup questions not because you're story isn't clear, but because they want to know more.
Questions - At the end of the interview (typically), they will ask if you have any for them. Don't say no and, if you've been networking for 3 months, don't ask about things you already know or should (staffing model, industry mix for that office, travel model, training, etc.). If you have real questions that need clarification, go for it. Also, consider your audience. Questions about timing or logistics for the next round should probably be directed to the recruiting coordinator, not your interviewer. I like to lead with "tell me what you're working on now." If it's interesting, you can easily fill 5-10 minutes just talking about their current or favorite project. It's also a good place to show off your knowledge that the pharma industry is consolidating due to firms having to make larger bets on R&D (I made that up) or whatever you read in the latest WSJ or Economist.
Final thoughts - Every interaction counts. If the firm has consultants greeting candidates in campus interview suite or in a conference room, don't blow them off because you're so focused on your "real" interviewer. These people provide feedback too. Firm handshake, confident introduction, lively conversation. This isn't hard; they're not there to grill you. Don't be a potato. Last, but not least, send a followup email the same day thanking your interviewer for their time.
Hope this helps. Feel free to ask about anything I didn't cover.