Many students in my class and other candidates do not develop their paragraphs well and put together a series of unrelated points. One reason they do this is that they forget it is a language exam and not a knowledge exam. They select their best ideas and not the ideas that are easier to write about.
It is stated in the IELTS writing band descriptor, under the band 7 Coherence and Cohesion, which you must “present a clear central topic within each paragraph”. Don’t break this rule! Many English native speakers or teachers write some sample IELTS essays in which contain two or three ideas in one main body paragraph. I don’t recommend any candidate plan or write essays in this way. Please follow my advice:
Make sure that plan ONE idea per paragraph. In the planning stage make sure you have enough to say about an idea before you start writing about it. This means that you may choose the ideas that are easiest to write about and not the ones that are the most intelligent.
Another advice is to think of some relevant examples for each of your ideas/paragraphs. Many candidates forget to use examples. This is a mistake because examples are often easier to write about than reasons.
Just think this way, one common question in IELTS reading test is to identify the main topic of a paragraph by selecting the correct heading from a list. One way to complete that task is to identify one sentence that gives the main point of the paragraph – this is the topic sentence. Your goal in the writing test is to ensure that each of your paragraphs contains a similar topic sentence. Learn how to write by thinking about reading.