Mens' hands. And backs. And shoulders.
But especially hands.
Those strangely industrial structures sliding under the skin of a good pair, dense and tight and yet still somehow elegant. So absorbing and revealing. So much of a person's inarticulate fundamentals can be read in their hands. Proportions, routines, compulsions, inheritances, expediencies, preferences... they're all there.
Have they ever lied to you? I don't remember them ever lying, in my experience. But I've made it my business to understand what they're telling me for a long time now. There should never be too much distance between what the mouth and hands are saying.