Structuralism Applied to Literature--Narratologists and Culler's "Structuralist Poetics"

        You would use Narratology or Structuralist Poetics to discover the deep structure rules which the text's characters and their actions express, much like the anthropologist studying children on a playground can begin to infer rules for behavior in their games from the kids' repeated gestures and sayings.  The first step always involves determining what binary oppositions are necessary to describe the text, and which of those are privileged (+ below) and which are what Raman Selden calls "privitive," or un-privileged (- below).  Then try to imagine the rules that operate those binaries in the text.  Your paper's thesis would explain how one or more of those rules work in the text, and perhaps, how readers respond to the rules you explain.  If this is not working for you on any particular work, try Northrop Frye's seasonal-generic "modes" or the generic "master plot" analysis of the work.

Narratology (Greimas [1966], Todorov [1969], Genette [1980]) The world and literature as we value it vs. the world and literature as artifacts Meaning is made by structuring artifacts in classes of opposed pairs (+/-) and actants operate to transfer desired objects/qualities.

Narrative structural units operate like linguistic units to perform sequences of actions form fundamental "propositions," the deep structure.

Narrative and narration interact according to tense (order/duration/frequency), and mood (distance/perspective/voice).

Literature functions according to the same rules by which we make sense of lived events, with the addition that literature must be assembled into meaning by the reader who must be following deep structure rules to "perform the text." 
Structuralist Poetics (Culler [1975]) The system of rules and codes for readers' performance and the corresponding structures of the properly performed text vs. literature as a mass of words on the page. Readers make meaning from literature by applying culturally prescribed rules for competent interpretation, including (in America) the rules of impersonality (literature is not life), naturalization (literary conventions will be rendered ordinary by experience),  significance (literature means more than ordinary discourse), metaphorical coherence (metaphors mean consistently within a text, though variously in many texts),  thematic unity (works are unified by some theme/point). Literature depends upon readers' mastery of complex conventions of interpretation which, consciously or unconsciously, react to deep structural rules by which we "create" the text we read from the words on the page.