Probably the greatest couturier of all time, in the photo the late Yves St. Laurent shows the rest of us how not to dress. His clothes are too perfect, too coordinated, and trying too obviously hard.
It cannot be said too many times that the essence of a man's dress is that it should not look as though he spent time thinking about it. Every ensemble needs a note of discord, or a sloppiness of some kind, and on this day at least St. Laurent lacked that bit of grace. His shirt picks up gray in the jacket and in the trousers and his tie and square pick up the maroon of the jacket. Indeed, tie and square may actually match each other, though we can hope that the photograph is simply not picking up the differences. In the end one is led to suspect that he is wearing maroon shoes.
Change a couple of items to related but different colors and textures, perhaps a black knit necktie and a dark silk paisley square, and the man would look a lot less posed and a lot better dressed. His shoes should be tan, or something equally uncoordinated.
It takes time to look as though a man spent no time on his clothes.