For non econ/finance majors - How Much Time Did It Take Until You Nailed IB Interviews?

I'm an engineer who SUCKED at interviewing until I got my story and technicals down. Had a solid GPA and good sophomore internship, but didn't have the social acumen (yet) to do the kind of networking necessary to get BB interviews. (Also never did diversity recruiting or women's focused programs at any time). 

Got interviews from lots of EBs though through their standard recruiting process. I had my technicals down-pat throughout recruiting, which I think EBs care more about, but it was the story and behavioral part for me that needed the most work. 

I sat down with friends until I had my story perfectly set and knew why I wanted to work in IB. They really drilled the exact things I needed to know to interview well and win my interviewers personally. 

It took me a solid 3 super days before I got it really, really down. I would say this covered approximately 3-4 weeks, in addition to ~2 months of interview prep with friends. 

Here are some suggestions:

• Give really good reasons for wanting to work in IB and the section you work in.
  • Cite what ways working in IB specifically interests you. Do not say something simple like "I like the valuation piece." or "The M&A process seems kinda cool." These are things everyone else says.
  • My example for Restructuring, "Call me crazy, but I actually enjoy learning about how companies hit the wall. Understanding what makes companies work well is just as complicated and unique as what makes companies not work well, and the debt restructuring process requires keen logical and legal insight. I got some experience with this at my last shop doing XYZ (a cool story about chicken-shit, I shit you not). After that, I started researching more about the restructuring process and learned from (examples) about (insights I learned from examples). I think this would be an awesome way to start my career with something that interests me so deeply." 
• When you network with the people at the company, ask if there is anything that they might want to see you mention in interviews.
  • Some companies (more so in LO AM, where I currently work) are looking for fairly specific answers to certain questions to properly assess fit
  • This is especially important at larger companies, where differentiating yourself is more difficult
• If there is something about you that is fun, interesting, and differentiating, talk about it.
  • This could be something as basic as skiing or complicated as coding simulations of the game Monopoly in my case.
  • Use the right thing with the right person. Be relatable. Some people care more about skiing, sports, and shotgunning beer (yes, we talked about how good we were at this in an interview once), others care more about finance books and current trends in the RX space.
  • Only bring up things that you and the other person have a connection with. For example, even though I was probably the only girl at multiple super days I attended, I never really brought up being a girl. I didn't once have a woman interviewer, except for some HR people, so I it was just something that never was talked a ton about

Good luck with interviews!