He by how she looks and the way she acts. Hot girls are the ones with the eprfect face, perfect hair, model body who are a little stuck up. Cute girls are the ones with nice curves, nice hair, maybe a little on the shorter side and have a bubbly personality. I'm more attracted to cute girls.
The first thing I look at is her face, if she has a cute face then at the very least she is cute. Then I look at the body to determine if she is hot, I look for any of the three: big breasts, nice butt, or great body: So if she has a cute face and one of the three other attributes then she is hot. If she has everything, she is perfectly smoking hot!
Yes, everyone does it. I mostly notice face then body. Then personality when I talk to them. All these factors are taken into account then my brain decides if they are sexy, cute etc. Personality also adds way more points to a first judgment of their physical appeal which can bump their score up.