After going through many interviews myself (both for medical school entry and medical positions thereafter), and having worked on panels for interviews (not for medical entry), here are some of my thoughts about dress...
Gentlemen:
Try as much as possible not to deviate from the standard shirt/pants/tie routine.
You are attempting to create an impression of professionalism, confidence and trust.
This is the beginnings of building your professional façade - individualisation comes much later in your medical career.
Your clothing should not draw attention away from your facial features, they should
not be distracting.
If you by chance visit your local hospital, notice what the interns and HMOs are wearing.
Dark coloured pants. No shorts. No tight/'slim' pants.
Collared shirt with button-down. No polos.
Tuck your shirt in
Avoid plain-weave solid-colour shirts (they are hard to keep tidy especially if you are travelling.)
As a
general rule: Pattern tie with solid-colour shirt. Solid tie with patterned shirts.
Please don't have a French cuff with cuff-links. Either button down your cuffs or use a plain knot for French cuffs.
Wear a watch - again, something that is not distracting.
Even if it is a hot day, don't wear short-sleeve shirts. Instead,
very neatly roll up a long-sleeve shirt.
No suit jackets or hunting jackets. You do not need a jacket. You should not wear one. Especially this time of the year.
Make sure your hair is neat. If you choose to style it, keep it lite. Use wax, keep it matte.
Get a hair-cut or at least a touch-up. Shave!
Brush your teeth (I once had to interview a young lady with some vegetable stuck between her teeth...this was highly distracting to say the least.)
Remove your piercings. (Somewhat controversial, I know...play it safe, this is an assessment, not time for personal statements.)
Dark coloured shoes, preferably Oxford style. Please, please, please polish your shoes, and re-sole/re-heel them if necessary.
Make sure your pants reach no further than the top of your shoe heels when standing - take them for a $15 hemming job.
Socks should match your pants.
Shoes should match your belt.
Tie length should just reach your belt.
Minimise jewellery.
Avoid skinny ties. Avoid bow-ties.
Learn how to tie your tie, and remember to adjust it before the interview (a slanted tie is very distracting!)
Don't put anything in your front pant pockets, and minimise the items in your back pockets.
Your shirt and pants should be of similar fit (it is
very distracting when one is noticeably more loose / more tight than the other.)
Avoid overly bright or contrasting colours.
[h=3]
tl;dr Not distracting, comfortable, neat, matching and unobtrusive.[/h]