I have always told my clients, "art is personal". If a client wants me to choose art for their styling, I will, but my rule of thumb in general is that they select the art, because art is sooooo very personal. My taste in art is very simple, normal, easy on the eye, pleasant, when you look at it you know what it is, no one has to explain to you what it means and it generally does not cause nightmares.
all images above from Elle Decor March 2014
Of course I realise if you are wealthy, art is an investment, but why does it have to be ugly? I am not wealthy. When I am, I still will not invest in ugly art. I will invest in fabulous furniture, fashion and shoes! One of my wall's, below, consists of art purchased from E-Bay. The pieces are pretty and visually pleasing, but I chose them because I like them and they fit my style.
Below is a client's parlour wall. The art consists of an inherited, amazing 100 year old cork carving (lower left) , a gift from a friend (far right, over 75 years old), a $5 watercolor from a sidewalk artist at the Met (top center), a Picasso poster and a $1.50 watercolor from a Colorado Springs 5 &10 back in the 60's. And it's fabulous!