to be dressed up to the nines = to look very smart

 

to be the height of fashion = to be very fashionable

Black is the height of fashion this season.

 

to be all the rage = to be very popular (old-fashioned)

Flared jeans were all the rage in the 90s.

 

a latest craze/fad = something that is fashionable for a short time

 

to be dressed in style = to look stylish

Getting dressed in style requires a great wardrobe with go-to pieces that can easily be mixed and matched.

 

to be happening = to look fashionable, trendy

He’s a real happening guy.

 

fancy shmancy = fashionable, impressive

Her fancy shmancy dress must have cost a fortune.

 

cheep and cheerful = “дешево и сердито”

 

to look posh = to look expensive and attractive

He looked posh. Smelt posh. Walked and talked posh. Even the way he was crouched behind the chimney was posh…

 

to dress with swag = to dress with style

 

For fun:

What is your fashion style quiz