Sometimes, instead of starting with a topic sentence and developing the topic in the body of the paragraph, we'll use the reverse shape -- a paragraph with several bits of evidence that lead to a final conclusory sentence:
Colonel Wallis had known Mr. Elliott long, had been well acquainted also with his wife, had perfectly understood the whole story. She was certainly not a woman of family, but well educated, accomplished, rich, and excessively in love with his friend. There had been the charm. She had sought him. Without that attraction, not all her money would have tempted Elliott, and Sir Walter was, moreover, assured of her having been a very fine woman. Here was a great deal to soften the business. A very fine woman, with a large fortune, in love with him! Sir Walter seemed to admit it as complete apology, and though Elizabeth could not see the circumstance in quite so favorable a light, she allowed it be a great extenuation.
~ Persuasion, Jane Austen
For those of you unfamiliar with the story, Mr. Elliott is the estranged cousin of Sir Walter. Mr. Elliott is trying to find his way back into Sir Walter's good graces. Sir Walter thought Mr. Elliott had married beneath him, beneath the family dignity.
So this paragraph leads us to understand that there will be a change of heart, that Mr. Elliott will be forgiven his bad marriage. It starts by setting out several points of information, all delivered by his friend, Colonel Wallis. Educated, accomplished, rich, and in love. Then it sets out that Mr. Elliott did not marry the woman for her money, as was previously believed. Then the coup de grace -- she was a very fine woman. Sir Walter, whose outsized personal vanity requires that everyone around him should be fashionable and beautiful, will forgive people almost anything as long as they are "fine" or good-looking and well-groomed.
It all leads to the final conclusion: Sir Walter forgives all, and his eldest daughter Elizabeth goes along with him.
In the blog comments, Green Knight mentioned a sudden tendency to use topical sentences in many of her paragraphs. A gently written topical paragraph will guide the reader from an idea into an exploration of an idea. But to break things up, try reversing the order of topical paragraphs on occasion -- save the "topic" or summary statement for the end of the paragraph, and let it serve as a conclusion to the paragraph.