The final sentence is your last chance to send off the reader with your message. Captive readers have had to read your whole essay, like it or not, while non-captive readers have chosen to take the whole journey with you. Reward both kinds of readers with a sendoff that is well constructed and leaves a good impression.
Let's examine Tocqueville's concluding sentence for a non-captive audience after hundreds of pages:
"The nations of our time cannot prevent the conditions of men from becoming equal; but it depends upon themselves whether the principle of equality is to lead them to servitude or freedom, to knowledge or barbarism, to prosperity or to wretchedness."
(1) "cannot prevent": be aware that equality is coming, like it or not;
(2) "it depends upon themselves": here is something we can do;
(3) "principle of equality": this is the central theme of the book;
(4) notice the pleasing either/or structure of the last half of the sentence.
Let's now conclude the Petruchio essay in the same style, for practice:
"We never can keep perfect control over the ceremonies that mean the most to us; but at least we can advise planning over anarchy, prudence over haphazardness, and tuxedos over leather."