Ask yourself what happened first, and what happened next. Write down the answer. Beneath each answer, detail all the events and instances that played a role in making it happen. For instance, if you are writing about causes and effects of the personal computer, PC, revolution, first describe the history behind the development of PCs, and then describe each development that led to the next change, such as the invention of the microchip. If writing about causes of clothing or a particular hairstyle fad, describe the people that may have influenced the change.
Write a thesis statement that captures what the cause is, and what the effect is. Structure it so that readers understand exactly what will be discussed in the paper. Use the words "cause" and "effect".
Write the detail to support the thesis statement, and the cause and effect named in it. Start a new paragraph, and fully detail all of the events in the order that they occurred, as well as their importance from least important to the most important.
Include transitions to combine the details coherently and cohesively. For example, use "first" and "next" to indicate the time order; "because" and "as a result" or "consequently" to reinforce that the first, one thing occurred, and then another -- or another cause and effect. Use "therefore" or "however" to add more personal supportive information.
Make sure your causes are direct; the less direct they are and disconnected from resulting effects, the more difficult it will be to inform or persuade your readers.
Include supporting evidence for each detail, such as any facts or statistics that describe details within the cause, effect, or any of the details therein. Use language that conveys the seriousness of the facts, such as "It is likely that..." or "Evidence continues to suggest...".
Conclude the essay by restating the introduction and thesis statement. Be sure to word it differently, and include a little more information or insight that wasn't included in the beginning. For example, if writing about the escalating costs of college tuition, add something about its offset through new availability of used book purchases online.