What's the best way to structure an IB paper one essay?

The two main ways to go about structuring your commentary are to explore the text either chronologically or by theme. The best way to choose between the two is often just to try out both and to see which you prefer. Personally, I prefer to structure my commentary by theme, this is because a) If i mismanage my time I can conclude my essay without leaving out an entire section of the textb) I find that it encourages me to think more analytically about the text at an earlier stage, in the planning process instead of the writing stage, which worked for me as it made the exam less intellectually demanding towards the end, when the time pressure stepped upbut you can achieve high marks in criterion C and a level 7 using either method.
Within the paragraphs themselves structure is also very important. In your introduction it is a good idea to outline briefly what the poem or text is literally about before stating the broader ideas that you think are explored in the text. This shows immediate understanding of the text and allows you to set out your argument [criterion A]. This often works well as a thesis statement ( a sentence that encapsulates the argument that you are making throughout your essay or commentary). The rest of the essay should be exploring this, i.e. using various literary techniques etc to explain how the author creates and portrays various atmospheres and events in order to explore these broader ideas.
A key thing to remember throughout your commentary is that it is not just a description of the text. In order to get the top marks you can't simply list the various language techniques etc that occur in the text, but also demonstrate how they are used [criterion B], the best way to do this is by thinking of these techniques not as the subject of the poem but as evidence that supports your way of interpreting the poem for example:
NOT the poem uses alliteration in order to show... BUT the author explores the idea of X particularly towards the end of the extract when Y occurs. This can be seen primarily in the use of alliteration throughout the...
Finally conclusions should not only occur at the end of the essay, but also at the end of every paragraph. Having a concluding statement at the end of every paragraph not only allows you to tie your analysis back to answering the question and maintain a clear sustained argument throughout but also makes writing the final conclusion much easier. At the end of the essay you are aiming to briefly summarise what you have argued throughout the essay, combining these concluding statements can make this much easier. It ensures that you have a clearer idea of what you want to say, this can save you a lot of time and stress at the end of the exam. In the conclusion, you can also include your own personal response to the text once it is answering the question. Finally having an ending that gestures towards what the ideas explored in the text can do for your life or the readers can prove your critical engagement with the text as a whole and not just the dissected parts that you have discussed throughout the commentary.