Paragraphs need to have a clear, central topic and be used logically. If your writing does not have paragraphs or the paragraphs are confusing, your coherence score will be no more than 5.
Common mistake: candidates do not develop their paragraphs and put together a series of unrelated points. For example, they love to put many reasons in one mian body paragraph. Remember, the reason why we use paragraph in writing, even in your first language writing, is to give a clear progression and structure to guide the reader understand you. 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 easiest to write about.
Solution: Make sure that each paragraph is about one idea. 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 solution is to think of reasons and examples for each of your main points. Many candidates forget to use examples. This is a mistake because examples are often easier to write about than reasons. And if you examine the question carefully, you will find the question asks you to "use example from your own experiences…"