Many students start writing essays without adequately planning or understanding the fundamentals.
Firstly, students must understand the different types of paragraphs their structure and use. As not all paragraphs are the same e.g. opinion and descriptive or process and compare and contrast.
Secondly, students must understand what a thesis statement is and how to write one. Many students that I have encountered do not fully understand the purpose of a thesis statement. A fundamental when writing an essay.
Finally, following the writing process. Many students just start writing without adequately gathering or planning ideas. The leads to a lack of unity in their writing and makes it difficult for the reader to understand. Therefore, students who follow the writing process, have higher results.
Writing essays is not easy, it takes a lot of practice. However understanding these three aspects can make the world of difference when you are trying to achieve good academic scores.