No matter how challenging and difficult essay writing may seem, generally accepted rules of writing are logical and easy to follow, as any well-written essay calls for a mind-developing thesis, solid evidence that support it and the counterarguments.
Motive and Idea
Any paper should have a purpose, and this purpose will never be a presentation of your knowledge of certain amount of material or simple collecting of information from one place to another. In fact, the paper should propose your fresh original idea you have come up with after the research of the material. Moreover, the idea has to be important as there is no need to argue the audience into the point of view that is already widely accepted.
Thesis and Development
Well-written thesis is an unspoken requirement of any successful paper. Of course, while you write the paper, the thesis may change, though it is inevitable as you have to focus all your efforts on establishing of the validity of the thesis. And you have to formulate the thesis in such a way that even people from other fields of study will find it understandable, interesting and important. Spark the curiosity of the audience with provocative questions and invite readers in the discussion.
Before even you start writing, you have to make a thorough research and find a lot of convincing and solid pieces of evidence and classify them according to their kind and strength. For example, you can star with the smallest one and move to the most solid or vice versa. Find evidence that surprised you and hold it to the end of the paper.
The Structure of Argument
You have to argue the audience into your point of view - and it is a hard work that calls for a context and effective way of revealing of the evidence. The most common structure of the argument is deductive: first comes the generalization and then goes support.