When I'm asked how to write "base paragraphs" for essays (sorta like what you're asking, i.e. paragraphs that you use as a base as you answer the question), without knowing the skill level of whoever I'm advising, I tell them to pick a central idea/theme (note that it must be relevant to your AoS theme!) and write a paragraph discussing it. Then you'd insert quotes, techniques etc from your text to serve as evidence to back up your claims in this discussion. After this is done, this will become your base paragraph. You'd answer essay questions using this base paragraph by using it to support your thesis (which should essentially be an answer to the question!).
For example, if your set text is Harry Potter (lol), you could choose to write about the Slytherin notion of pureblood supremacy and "mudblood" muggleborns. If you get an essay question that asks you about how HP is a mouthpiece for its author, you could argue a thesis along the lines of "HP is a mouthpiece for Rowling in the sense that current social issues prevalent in England, where Rowling was born and raised, are reflected within the HP universe, and it can thus be concluded that they are Rowling's own interpretations and opinions of those issues." You would then support this thesis by discussing that one of these issues are racism, which is present within HP as pureblood supremacy, then elaborate on your base paragraph by saying that pureblood supremacy promoted by the Slytherins is a metaphor for racism against the backdrop of modern England, which is J K Rowling's homeland, and as such, whatever message is being promoted about pureblood supremacy in the books can be interpreted as Rowling's own response to the racism that is rampant in modern England.
Apologies in advance for the verbosity of this entire post, and for the laughable example using HP. I'm half asleep and words are hard to connect properly, lol. Best of luck for your studies!
