Of the formal rules of writing an essay, there is only one - the presence of a title.
The internal structure of the essay can be arbitrary. It is not necessary to necessarily repeat the conclusions at the end, they can be included in the main text.
Argumentation can precede the formulation of the problem. The formulation of the problem may coincide with the final conclusion.
Unlike the abstract, which is addressed to any reader, the essay is a rejoinder addressed to a prepared reader . That is, a person who already has a general idea of what will be discussed in academized review. This allows you to concentrate on revealing what is new and not cluttering the narrative with service details.
Mistakes when writing an essay
Poor checking. Don't think you can limit yourself to spell-checking. Reread your essays and make sure there are no ambiguous expressions, unfortunate turns, etc.
Tiresome prefaces. An insufficient amount of detail. Too often an interesting essay loses out in being a listing of statements without illustrating them with examples.
Verbosity. Essays are limited to a certain number of words, so you need to manage that amount wisely. Sometimes this means leaving out some ideas or details, especially if they have already been mentioned somewhere or are not directly relevant.
Long sentences. The longer the sentence, the better, some people think. However, this is far from the truth. Long sentences do not yet prove the author right, and short sentences often have a greater effect. It is best when long phrases alternate with short ones in an essay.
Don't overload the essay. When writing an essay, discard encyclopedia words. Incorrect use of such words distracts the reader's attention and diminishes the importance of the essay.