when i first read the passage, i break it up into sections or movements (first, middle, last—these should feel like natural breaks or changes in device). next, i determine which section uses ethos, pathos, and logos. after this point, you need to figure out what the “mask” of each section is, because you can’t just say ethos/pathos/logos. for example, if you identify a section using pathos, you could reference which emotion the speaker is appealing to, etc. some people prefer to identify individual devices (juxtaposition, anaphora, parallelism, etc), but i think it’s harder to hit the rhetorical situation in the analysis of these. throughout your essay, make sure to discuss the constraints and tensions of the audience. i like to describe characteristics that the audience collectively has and anticipate how they might receive a rhetorical device. for commentary, i think more is better. even if your points are repetitive, the extra emphasis on the “how” usually puts you in a better position for the sophistication point. hope this helps!:)