How should you structure an unseen commentary?

There are three main ways to structure an unseen commentary: chronologically, technically and thematically, but I would argue that the latter is the most useful. First read the passage at least twice before lifting a pen, and then try as quickly as you can to group the poem into different themes converging around a single overarching thesis. This thesis must represent an argument about the text's message eg. it displays the oppression of women, and then the themes must prove this idea eg. objectification of women, their lack of independence in the passage etc. Once you have done this you then merge your technical comments on the poem, so analysis of rhetorical devices and language features, within your thematic paragraphs so that the entire essay is not only a commentary but actually a generalised about the message of the text.