formal shoes (make sure you break them in before midyear!). For girls: backup flats (I used to carry these in my bag and they were a life-saver!)
Casual wear in case you actually have time to hang out (some people completely forgot to bring this and ended up wearing suits everywhere...)
A padfolio (I found this very helpful to keep all my resumes, notes, schedules and business cards. Plus it makes you look professional)
30-40 copies of your CV or ~3-5 for every position that you apply to (especially if you apply to the Rutgers program since there are 3 rounds of interviews and multiple interviewers per round).
Business cards (optional). I spent a lot of money making business cards but ended up hardly using them so I’m not sure it was the best investment. If you do bring them, consider attaching them to your CV with a paper clip
Hard copies of any fellowship brochures. It was extremely helpful to flip through these before interviews
Thank-you cards (~50; optional).
Hard copies of all your presentations, journal clubs, research posters, and publications
A schedule sheet that lists the day and splits it up into times for interviewing to track which interviews you have scheduled.
Water and snacks
Pro Tip: if you are checking luggage at the airport, bring a carry-on with some CVs and one suit if possible – people have had their luggage lost in the past, this way it will be one less thing to worry about if that happens!