James Joyce (especially “The Dead” in Dubliners) and any story collection by the following: Flannery O’Connor, Alice Munro, William Trevor, Heinrich Boll, Raymond Carver
I could add that Rudy Wiebe, of our own country, has a very good Introduction about the short story in an anthology he put together many years ago called: The Story Makers.
Mavis Gallant, Garcia Marquez, Franz Kafka, Samuel Beckett, James Joyce, Guy Vanderhaeghe
E. Pauline Johnson, Dorothy Livesay, Irving Layton, Nicole Brossard, Li Po, Ezra Pound, Marilyn Dumont, Rita Joe, Lawrence Fusado Inada, Auden, Yeats, Keats et. al.
Edith Kanaka’ole and Buddhist chant, for breath
And because we insist on the confessional: Robert Haas, Sharon Olds, Donald Hall
Read them all, imitate, then walk away
William Carlos Williams, H.D., Jack Spicer, John Newlove, Robert Creeley, Victor Coleman, Erin Moure, Robin Blaser, Margaret Avison, Robert Kroetsch
I admire a lot of poets from earlier times, poets that might not serve as good practitioner models for poets who want to learn composition. (And I always do prompt new poets to imitate the poets they like, keep at it until their own methods emerge.) Poets such as Shelley, my favorite, should be read, but maybe their language is more early 19th C.