Without being annoying make sure people know your name. If you're on a surgery clerkship and your scrubbing with 5 different surgeons throughout the course of a month they may not remember who the hell you are when its time to evaluate you because they certainly aren't paying much attention to you in the OR. When its appropriate, introduce yourself and make conversation to get some face-time. The key here is "when its appropriate." You'll have to use your discretion again, just don't be annoying about it.
Engage in casual discourse with your residents as appropriate. I found this particularly easy on surgery because I am a guy and I want to do surgery (sorry if that sounds sexist). You're not assigned to a service so that you can make new friends, but if the opportunity allows for you to get dinner with the residents on yoru team and talk about stuff outside of your clinical duties then by all means do it. We're all human. However if this isn't going to happen because your personalities just don't mesh, then don't force it. People may have positive memories about you that have nothing to do with medicine. That is a good thing when its time for them to evaluate you but it is not necessary. For example I didn't really have much in common with people on my pediatrics rotation, but I still got honors without really doing anything besides showing up on time and working hard.
There is a lot mroe to this category, but the bottom line is that the more people like you the more likely they will be to evaluate you highly on ANY PART OF YOUR EVALUATION whether you deserve it or not. This is psychology people.