To the OP: keeping your MOUTH SHUT goes a long way in being noticed these days. When we have students, the quiet, mature, efficient one (the "Stealth Bomber") is ALWAYS the one I appreciate and notice the most. Seems counterintuitive to what HouTx says but, when the majority of clinical groups are little gangs of cackling, giggling, wide-eyed, asking-questions-and-babbling-nonstop, whining and complaining types....... the one who quietly knows her stuff, gets things done, arrives early and leaves late, notices things that need attention and takes care of it without making a fuss (even just picking up a piece of trash on the floor and throwing it away, or straightening a stack of towels without being asked), is considerate of WHEN to ask questions, takes notes, and has what I call a "low BS quotient" is the one who definitely gets noticed.
This can also include your appearance. Simple hair, minimal makeup, no jewelry, clean pressed scrubs & short nails. People who LOOK low-maintenance usually are.
Don't smoke. I can smell you a mile away if you do and that definitely pushes you down a few notches in my book.
Save the drama for your mama. If you make a mistake or don't know something, no need for hysterics. Also, cryers and fainters are definitely viewed negatively.
Have a sense of mature, intelligent humor when appropriate. I can't stand nervous students who laugh every 3 minutes to cover up their nervousness. Or seem to only know humor from dumb TV shows/movies. Just shut up if you can't offer anything halfway intelligent.
Really, that quiet student who gets things done and isn't a braying donkey is the one I notice!