The style of the work in part grows out of Eliot's interest in exploring the possibilities of dramatic monologue. This interest dates back at least as far as "The Love Song of J. Alfred Prufrock". The Waste Land is not a single monologue like "Prufrock". Instead, it is made up of a wide variety of voices (sometimes in monologue, dialogue, or with more than two characters speaking).
The style of the poem overall is marked by the hundreds of allusions and quotations from other texts (classic and obscure; "highbrow" and "lowbrow") that Eliot peppered throughout the poem. In addition to the many "highbrow" references and/or quotes from poets like Baudelaire, Shakespeare, Ovid, and Homer, Eliot also included a couple of references to "lowbrow" genres. A good example of this is Eliot's quote from the 1912 popular song "The Shakespearian Rag" by lyricists Herman Ruby and Gene Buck. There were also a number of lowbrow references in the opening section of Eliot's original manuscript (when the poem was entitled "He Do The Police in Different Voices"), but they were removed from the final draft after Eliot cut this original opening section.
The Waste Land is notable for its seemingly disjointed structure, indicative of the Modernist style of James Joyce's Ulysses (which Eliot cited as an influence and which he read the same year that he was writing The Waste Land). In the Modernist style, Eliot jumps from one voice or image to another without clearly delineating these shifts for the reader. He also includes phrases from multiple foreign languages (Latin, Greek, Italian, German, French and Sanskrit), indicative of Pound's influence.