Art is any function of life that is performed as it should be performed.
The subjectivity inherent in "should be" might irritate some, but they must remember that art is no more art when it is deprived of subjectivity. Everyone might have his own ethics, and that governs the functions his life which is, from an aesthetic point of view, his art. Now, even smoking, if performed properly, might be somebody's art. But what about universality? I think art's universality lies in the vastness of your subjectivity. The closer your experiences are to life, the more acceptable they are to those who live... Because definitely life is common to all of us!