Discuss brainstorming. Give examples of a theme, such as motorcycles or professions, and come up with ideas together. Explain how never to deviate from the title when the essay task is specific.
Present the five-paragraph essay first. It's the core essay format: main idea, three paragraphs explaining it in detail and conclusion. When children have fully understood its structure -- after lots of practicing -- move on to compare and contrast and cause and effect essays.
Examine each part of the essay separately. Children must learn to write concise introductions, which present the main idea and relevant background information. At first, assign introductory paragraph tasks, instead of practicing full essay writing.
Follow the same pattern with the conclusion. When students have realized the distinct role of the first and last paragraph, start collaborating to create short but complete essays in the classroom.
Create a drawing on the board for two different things that you need to compare. Try to depict most of their basic differences (for example, make the football field bigger than the basketball court) and discuss with children about similarities and differences. Explain how these attributes can be presented in an essay, as two paragraphs of similarities/differences or with each paragraph focusing on a distinct issue.
Narrate short stories when cause and effect is easily understandable and let children find the connection themselves. With careful questions (just like Socrates did), try to make children come up with the answer by themselves. For instance, why did the postman quit his job? Because he was upset. Why was he upset? Because dogs were constantly after him.
Present children with examples of essays of a specific style or on a particular subject. If guidelines seem a bit vague for students, an example of a similar, well-written essay will be a major help. Make sure you warn them about plagiarism and its consequences.