There is a passage in a story by Stefan Zweig, a wonderful writer not much read these days, where he describes the hands of gamblers in a casino. The narrator, a bored widow dying of sexual frustration, goes to the casino every day to watch the hands of gamblers. She never looks at their faces. She knows that the faces are composed for others, posed to look indifferent or stoic, to not betray emotion. The hands, however, are unselfconscious; they are avaricious, hungry, fearful, amused, aroused, filled with the nervous tics of their owners, jumping with energy, fingers intertwined to keep themselves still, constantly being restrained, reflecting character and emotion. One day, she sees a pair of young, aristocratic hands in an extreme state of excitement, more expressive than any hands she has ever seen. Thereby hangs an amazing tale called "Forty Eight Hours in the Life of a Woman." I don't want to give it away -- it's better if you read it yourself.
Laura and I once sat in a cafe on a busy street watching people's shoes as they walked by. We tried to guess from their shoes what their owners did, who they were, where they were going, what they were running from. We had no time to confirm our impressions by comparing them to their clothes or faces because they went by too quickly, but we intuited in quick flashes entire destinies expressed in sandals, boots, dress shoes, pumps, stilettos and sports. Chances are we were right because we also considered, however unthinkingly, the shoe owners' walking styles. It now turns out that the FBI is developing an identification system based on walking because every person's walk is as individual as a fingerprint. Or so they say. God forbid you should start dancing as you walk: they might get you for impersonating a sprite.
People will rarely let you know them through words or faces or any upfront body part. Watch the sections that don't get much press: necks, hands, feet, ears, and knees, and then you too can be a devilishly observant writer, just like me and Zweig.