A ‣ Hair, face, skin and complexion /kəmˈplekʃən/ 
What sort of person would you find attractive? Blonde, fair, dark or ginger-haired / red-haired?
She has such beautiful auburn hair. /ˈɔːbən/ [red-brown]
Fair and dark can be used for hair, complexion or skin. Some people like getting a tan in summer. [exposing their skin to the sun so that it goes darker], although the risks of getting sunburnt are well known.
B ‣ Height and build
Fat may sound impolite. Instead we can say that someone is rather plump or stout, or a bit overweight. If someone is broad and solid, we can say they are stocky. A person with good muscles can be well-built or muscular. [generally said about men] Someone who is very fat can be described as obese /əʊˈbiːs/, especially when talking in a medical context.
Someone who is thin can be described as slim [positive] or skinny [negative]. If someone has a nice figure, they have an attractive shape. [generally said about women]
C ‣ General appearance 
She's a very smart and elegant woman, always well-dressed; her husband is quite the opposite, very scruffy and untidy-looking / messy-looking.
Chloe looked stunning in her red dress. [very attractive]
He's very good-looking, but his friend's rather unattractive. [opp attractive]
Her eyes are her best feature. [the most attractive part of her face]
Do you think beautiful women are always attracted to handsome men? I don't. I think personality matters most.
First impressions are always important. [your first reaction to someone]
Language help
The suffix -ish is useful for describing people (see Unit 70).
She’s tallish.
He has brownish hair.
He must be thirtyish / in his thirties.