People have been saying for the better part of one hundred and fifty years, if not even longer, that one can deduce someone's personality simply by looking at their face. I've always thought the notion was maybe twenty five percent true-- but it turns out it's more like seventy two percent accurate.
Their use of the "Big 5" personality traits might be causing some of the twenty eight percent inaccuracy: one thing I've noticed over the past several years is that the Left and Right have become muddied on some of those.
For example, the Left used to be known for their openness to new experiences-- but today, they are intensely terrified of new experiences, opting for crayon books, nostalgia, and "safe spaces." Whereas, people on the Right today are the ones "peeling back the onion", challenging their own perceptions of-- to borrow a book title from Murray Rothbard-- "Man, Economy, and State".
As for anecdotes, I've noticed on the male side that the more square jawed someone is, the more likely they are to be on the Right: in the cities it's effeminate hipster types, and they are almost on the Left; up North while meeting with contractors, it was striking to me how masculine they looked, and I could tell from their demeanors and little off-hand remarks that they were on the Right.
On the female end, Leftist women often have that unmistakable look of taught skin and thin lips-- whereas women on the Right often have more robust facial features and expressions.
None of this is fool proof, and everyone should be treated and understood as an individual-- but it's a good starting point.