Dear Aspirant,
Post-modernism is one of the most intriguing ways of approaching literature. Post-modernist critics do the following:
1. They search for the themes of post-modernism, the recurring patterns, and the cultural, political, social and economic factors relevant amongst the literature of the 20th century and deal with their implications.
2. They seemed to be concerned with the disappearance of reality. They also guard the identities of the post modern era.
3. They pay emphasis to the 'intertextual elements' in literature noting the external realities of the text. They look at all literary devises and analyse it in multiple contexts.
4. They foreground irony, in the sense, the modernist tries to destroy the past but the postmodernist realized that the past must be re-visited with irony.
5.They looke at the element of 'narcissism' in narrative technique, that is, where novels focus on and debate their own ends and processes and thereby 'de-naturalise' their content.
Hope this helps. All the best!