Briefly, because this is a big topic, the poetic styles of modernist poets T. S. Eliot, Dylan Thomas, Philip Larkin, and H. W. Auden compared as follows. Prominent characteristics of Eliot's poetic style emphasize the "careful crafting and arrangement of lines and phrase" (eNotes). Eliot drew very heavily upon allusions to historical, classical and other literary sources. For this reason, some critics of his early work thought of him as a plagiarist. It is the "crafting and arrangement of lines and phrases" that lifted him out of the cellar of plagiarism and elevated him to the level he now holds as creative poet.
Eliot used allusions because his poetic aesthetic recognized nothing new is created unless it is built upon all that has come before. His style also emphasised bold, even dramatic language, vivid imagery, and complex symbolism. His prominent themes include identity, religion, sexuality, and the nature of love. He matches his vocabulary and diction to the emotional state conveyed by the poem so that the two enhance each other. He was influenced by poets from Shakespeare to Symbolists (eNotes).
Dylan Thomas (eNotes) eschewed (stayed away from) traditional poetic forms. He typically wrote lines in tetrameter (four stresses per line) in iambs or anapests. He varied the stresses in the line and from word to word within the lines in an unconventional manner. For instance, in a line of poetry, he may stress a single syllable word so as to create two syllables from it as with "clean" in "the cle -an' bones gone." Thomas also relies upon alliteration, coupled with "end-rhyme, assonance and consonance" (eNotes). He often composed sonnets, though with his own unique form differing from both English and Petrarchan forms.
Philip Larkin's poetic style was influenced by the historic and political times he lived in. His distrust of modern, urban, technological society caused him to focus keenly on simple people "in touch with the land" (eNotes). After seeing world war, he also witnessed the breaking up of the English empire as colonial countries were given their independence. All this influenced him to shun symbolism and metaphor. He wrote instead in the plain language of "discursive verse" (eNotes). Since Larkin had little use for poetic devices, he relied upon keen observations and upon the important themes of alienation, isolation, and distance. These he embellished with irony, judgementalism, complacency, and smugness, offered up in colloquial language that didn't shrink from being "coarse, vulgar, or profane" (eNotes).
W. H. Auden has some similarity with Larkin in that he, too, is heavily influenced by the trying modern times; avoids traditional poetic devices; and places dominant reliance on theme. Auden's style utilizes strong, dramatic language, which marks him as different from Larkin, though Auden's aloof and arrogant tone create a distance similar to Larkin's (eNotes).
Auden's exceptional intellect carries him through three periods of examining the nature of love. His early poetry chronicles the inability of modern people to find love. In his second period, he offers a solution to this inability through love enlivened by "human sympathy and, later, by religious belief" (eNotes). His final phase reflects his changed perspective that sees even modern life as "blessed" and defines love as a redemptive power that overwhelms the times. This last phase introduces a light, comic tone that replaces the distancing tone of his earlier poetry.