I think you hit the nail on the head with your comment about not looking like a gunner. That is more important that people realize, I think.
Specific advice of mine would be to ALWAYS be positive, energetic, and intrigued. Attendings love teaching students that love to learn. Even if you haven't slept for 36 hours, you should still try and find the energy to be positive. No normally developed attending will give a horrible grade to a guy that loves to learn.
Do article presentations when you can. If you are on a rotation by yourself, then let loose with the articles. If you have other students on the rotation, be sure they're on board with their own presentations (so you don't look like a gunner).
Patient presentations are also important. Emulate the style of your residents, but be more detailed. Read the relevant Up To Date article on your patient before presenting. Do this even during clinic when you are seeing a bunch of patients. No one will remember that you did less patients than everyone else, but they will remember a bad presentation.
Anyone else have advice that I missed?