But what I sometimes do is look into the person's eyes. I always felt that a person's soul is reflected in their eyes; whether they're happy atau upset, kind-hearted atau cold-hearted, bubbly atau mysterious, all kinds of things. Of course I don't completely rely on that, but it is something I regularly do when meeting people.
Only downfall is that I probably end up staring at the person, because they give me this awkward "WTF?" facial expression and tend to seemingly avoid me.