Basically speaking, one who reads the Midrash should always observe how and why the author omits certain details so that a lesson in the law can be learned, thus formulating one's own explanation of the law or story. Overall, the purpose of the Midrash is to teach two important traits -- first, to "explain to the student the meaning of ambiguous texts and their often difficult vocabulary and syntax" in order to arrive at an appropriate explanation for the law or story, and second, to "describe the personalities and events in the Torah so as to make them recognizable and relevant to contemporary minds" (Goldin, 67)
Overall, the study of the Torah through the eyes of those that read the Midrash must result in peace of mind and peace within the soul, two traits that were often highly stressed by the great patriarchs, whether in the traditional holy scriptures or in the Midrash. In essence, it is a school where "learning is to be found, wisdom acquired through interpretation of the Torah" (Miller, 245)
There are also others that comment only on the first verse and then proceed to discuss those that follow it. In some Midrashim, one may find an introductory statement that serves as a preface to the main interpretation which some scholars believe "served as brief sermons before the actual reading of the Torah" (Neusner, 178)