First formulate your thesis (your claim). The thesis is a declarative sentence that in one sentence identifies the basic point of your essay. After reviewing the research from last week, decide the most convincing/strongest evidence you have in support of your claim. You are writing an academic essay, so your evidence should be rooted in logos. Identify the strongest counterarguments and decide whether you should acknowledge or refute the counterarguments or perhaps you will need a combination. The strongest kinds of evidence are reasons, facts, statistics, and expert analysis.
Think about your audience and analyze the best way to use logos, ethos, and pathos in your essay. Your audience analysis should also indicate the order of your evidence. Is your audience already somewhat convinced? If so, you might start with the strongest evidence. Is your audience hesitant to agree with your claim? You might need to begin with your less strong claim and walk you audience through your reasoning.