An essay has a not quite standard structure. It should have no table of contents, no list of references, and sometimes not even a title page. It is a free genre, which can be expressed by the author as he or she wants. The only condition that determines the structure of academized review is logic. Everything must be structured according to the laws of logic. The scheme of essay writing does not change much regardless of the size and remains the same even in a mini essay.
Despite the fact that the essay has a free form, it has structural features. First of all, they are caused by the requirements of this genre:
All the author's thoughts must be stated in thesis statements;
Each thesis must be supported by arguments.
Arguments in this case are specific well-known facts, events, phenomena, objects, scientifically proven facts, etc. The author's phrase: "My grandmother told me about it" cannot be considered an argument. References to books or films are appropriate.
An average essay usually has a small size (the standard length is several sheets of A4), begins with a statement of the problem, followed by the statement of several (usually three) theses and 2-3 arguments to these theses. It all ends with a general conclusion.
An alternative form of writing is also possible. The statement of the problem remains the same. It is followed by the first thesis and arguments in its defense. And then comes the mini-conclusion on this thesis: thesis + Argument 1 + Argument 2 + Argument 3 + Conclusion
This sequence is repeated 2 or 3 times, depending on how many theses you are operating on. And in the conclusion of this essay, there may not be a general conclusion. There is also a third option, how to write an essay essay: add an opinion of the opposite side and the justification for its fallacy. This type of composition is more thorough and serious.