Focus on topic sentence
There are five important ways to construct an impressive paragraph. Among the five ways, the foremost way is to build an attractive topic sentence. Make sure the topic sentence contain the clear-cut idea of what the passage will follow. It is meant to be comprehensive and must have the main idea of the passage. Therefore, it needs to be thoroughly worked upon to enhance the look of the paragraph.
Another thing to consider in paragraph writing is the unity of topic. Make sure that all the sentences of the passage are connected to each other. It implies that the supporting sentences in the passage must be linked with the central idea. They should not seem to be taking from another passage. Thus, there must be uniformity in the structure of the paragraph.
The consideration of coherence is also an important factor in paragraph writing. The passage must be in a logical format. There must be continuity and flow in the ideas conveyed in writing. For your ease, keep in mind that in any writing, each paragraph explains a single idea. So each passage must be able to fully describe a particular point. Some keywords in the passage must be repeated many times to give a coherent look to it.
Also, you have the option of adding a concluding sentence in the paragraph. It is not must to include but if you add it, it would give a neat look to the whole passage. Be assured that this sentence covers the entire idea of the paragraph comprehensively.
Lastly, the passage writing requires the great deal of tact and expertise. Practice writing few paragraphs on daily basis. Being a freelance writer, it becomes necessary for you to write an effective passage. So practice a lot and become adept at paragraph writing.