At its core, argumentation is an attempt at persuasion. At this point, you should already be describing the reasons that defined the thesis statement. Devote a small paragraph to each of them and make sure each one is complete, play on their contrasts--try to make sure that each subsequent paragraph is different from the previous one without breaking the logical chain. The main criteria you need to follow in your argument: subject matter, sequence, chronology, and contrast. Avoid one-sentence statements: you must build context for each argument. Remember that the thesis statement can also be given at the end of the paper; don't lock yourself into a strict sequence of highlighted parts.