Fleshing out Words

How do you make a character come alive on a page? It's all a matter of words. The maxim for the film industry is "Show, don't tell", which is well and good when you have a camera handy. If the only tools at your disposal are words, then it get a bit more tricky.
For example, I'm working on a story that has a doctor in it. I could easily have the guy say "I'm a doctor", but that makes him little more than a sock puppet. If the guy says he's a doctor, that doesn't mean anything. We form relationships by people, not by titles. This might seem like a broad statement to say, especially considering the pathetic state of society right now, but it's true.
So let's try that again. We could write "Joe Schmoe put on his stethoscope and walked out of his office at the hospital." Better. Not good, but not horrible either.
How about building on that with, ""Turn your head and cough, " Joe Schmoe said, shivering in his chilly office at Mercy Medical Center"
That's getting there. But the most effective method of making a character come alive is to suggest and insinuate. Let the reader gather all the pieces of the scene you're setting. Trust the reader to put it all together. In a sense, that's what we do in our daily lives. We don't wake up and get a synopsis of how the day is going, we gather little clues as we dress and brush our teeth. By the time we're ready to head out the door, we've got a pretty good idea about what's in store for us that day.
One more time. "Joe Schmoe draped the stethoscope over his shoulder as he locked his office in Mercy Medical Hospital. "When are patients going to learn that not all doctors are obsessed about health insurance," he wondered. "Most of us joined the profession to help people, not just to line our pockets," he muttered.

Something like that.