One way to improve Coherence and Cohesions scores is to include previews. Previews tell the examiner what to expect in the essay before they read it. This will show that the essay is carefully organised, and help to make sure there is a logical order to your writing.
Previews are usually the last sentence in an introduction (previewing the main points) or in topic sentences (previewing the sporting points within a paragraph).
Below is an example where the preview is the final sentence of the introduction:
In the last thirty years the world has witnessed an almost unimaginable improvement in communications technology. These days, tasks that used to require face-to-face interaction (such as shopping and working) can now be easily achieved at a distance using computers or mobile phones. This change is enormously beneficial as it not only saves vast amounts of time but also benefits the environment by reducing travel.
In this introduction the sub-claims of the main paragraphs are clearly previewed. The reader can then expect that the essay will examine these points in the order presented in the introduction. This helps the reader to follow the arguments as they develop, ultimately improving coherence.
However, sometimes it is necessary to preview points in the topic sentence of each main paragraph when more than one supporting point is used:
A lack of exercise and a lack of knowledge about food are the principle causes of increasing weight and declining fitness. People are often unable to find time to exercise due to work pressures, and cooking is not a part of the education system so many are simply ignorant to the harm a bad diet is doing to them. Without enough exercise, people gain weight as they are not burning enough calories, and without culinary knowledge people turn to ready-meals and processed foods that are high in sugar and have hidden ingredients that are known to be harmful. The result, therefore, is an overall decrease in health and fitness throughout the nation.
Many test-takers simply write main points without any previews. The result is that examiners lose track of an argument or become surprised when a new point is raised, resulting in a lower grade.