What is the first thing you notice about someone?

When you first meet someone, what do you notice first? Their shoes; their clothing; their hair, their smile, the color of their teeth, their fingernails? What is the best accessory someone can have; that they should never leave home without? When I first notice an individual; I notice their postureā€¦ It says a lot about a person. Someone that stands up straight; looks forward not down; says confidently. A person who slouches and hangs their head low; says, uncomfortable, and perhaps give a vibe that they are unapproachable and unfriendly. I am not suggesting that this is true all of the time; just that it is the first impression. I believe that a person that always carries a smile; carries their most precious accessory. Smiles, as well as a frown, are contagious.
So how about you; what do you first notice on a person? What is the best accessory?