Ill throw my hat into the ring here, as someone who works in the finance industry:
Suit colors:
I would not go to an interview in a black suit under any circumstances. This is just my preference, but I believe that black suits are for weddings (in which case you should be wearing a tuxedo) and funerals. Many people I know share this view, it just seems to clash too much. This is unfortunate because literally everyone wears black suits to their interviews. Don't be that guy.
Navy & Grey are your best options. When in doubt, go with Navy Blue, it looks good on literally everyone, and will set you apart from the sea of black suits. If you can pull it off, grey flannel is a great color & fabric and can set you apart even further while keeping it professional.
Suit Sources:
I get all my suits from the JCrew Factory Outlet. I don't use the online suit services because many of them use poor quality material & I prefer to actually try the suit on before I buy it.
You can get a full suit for around 300-400 USD from the outlet, and you wont need to get it tailored much to achieve a perfect fit. I bought suits from Jos.A Bank for a while, but even when they are tailored they don't fit well. They are far too baggy, being designed for a middle aged man more than a young professional. The outlet also sells dress shirts that fit very well and are of good quality. You really can't beat the pricing on these either (40-50 USD)
Dress Shirts:
For a medical school interview your collar type doesn't really matter. I happen to love the oxford collar, and oxford shirts in general. They give a more academic look than the classic flat collar dress shirt. They just look "preppier" which I think is a good thing, you don't want to look like you're there to sell stocks and bonds. If you are going to a job interview in the business world, you need a flat collar, oxfords will reflect unprofessionally on you.
Colours should be mute, Stark white is good but make sure it's ironed or it'll look sloppy. Light blue pinstripes on a white shirt look good, and is a classic oxford pattern. Light blue solid is another good choice, but be careful it isn't too blue, especially if you're going with a Navy suit. Now isn't the time to assert your individuality or creativity. Keep it professional. No crazy colours, no crazy patterns. If you show up to an interview with me in a pink dress shirt with a white collar and blue cuffs I will slap you.
Fit:
You should be looking for a suit with a modern fit. English-Cut suit jackets will be your best bet on this. If you are really lanky, you're really really going to want to get your suit tailored. Nothing looks worse than a skinny dude in a baggy suit. Its just unprofessional. Ditto to heavier dudes wearing spandex-tight suits. It shouldn't fit like a gimp suit. When in doubt see a tailor who knows modern suiting.
I like the fit of the suits from JCrew & Ralph Lauren.
They have a really modern fit, which I absolutely love. I have several suits from different brands, and the fit varies widely by brand. I have a pretty athletic build, and the JCrew suits fit me perfectly.
Shoes:
Oxfords or Monk-straps are your best bet here. Please for the love of god don't wear black pleather shoes. If your shoes can't be shined then they aren't appropriate for an interview. If they look like something a waiter at chili's would wear, they aren't appropriate.
Black coloured oxfords are okay, but you need to keep them shined & clean if you're gonna wear them. If they are beat up & dingy it is very noticeable, especially if you are wearing a black suit.
I prefer brown shoes for almost every situation. Your shoes should always match your belt.
To my most recent interview, I wore a steel gray suit, with walnut coloured oxfords and a matching belt. Finished it off with my lucky Navy-Blue tie (gift from my late grandfather). I honestly felt like I stood out in a positive way from the sea of poorly-fit black suits.
One final note, make sure you don't show up to the interview with a scrappy looking goatee or chin-strap. For the love of god. I saw people who did this at my interview and it was painful. Please just shave, do yourself a favor.
and comb your damn hair.
love,
RogueBanana