Every program seems to have different expectations out of student rotators from glorified shadowing to actively updating the list and being involved in decision-making. What are some initiatives that medical students can take in your program or programs you've seen which are impressive and set them apart?
How about at interviews when there is less time to "impress?"
This question has been answered umpteen times, in books, articles, and forums.
Be available, affable, and able.
Work harder than you've ever worked - figure out what Sub-I's can do at that institution (scrubs for cases, move patients, collect labs, check on patients) and be the absolute best at whatever that is. I don't care if you can operate. I care if you can do the work a neurosurgery resident needs to do.
Be normal. THIS CANNOT BE OVERSTATED. If you sense the residents need help, try to help. If you sense they don't want anything to do with you at that particular moment, back the hell off and be more of an observer. Make friends with the scrub techs, nurses, and support staff, but don't be patronizing. Be the kind of person we want to spend 7 years with, not the person on a permanent job interview.
Being a sub-I is hard, and you're more likely to be forgotten come rank list time unless you're truly memorable. We typically have 1-2 sub-Is (out of 20+) per year that we actually remember come rank list time. The rest blend in with the pack.
Expectations depend on program. Some range from glorified shadowing to acting like an intern writing notes, seeing consults, etc. Day 1 ask the chief resident or whoever you're assigned to what the expectations are. Do what you're expected because most don't even do that.