There is no single 'right' way to approach a critical essay but the following pointers will give you guidance.
The introduction should not be too long and detailed and it should focus on the question right from the start.
In a sense, the introduction should be a summary of the whole essay – later paragraphs should not change the direction of the argument or introduce new and unexpected topics.
Here is an example of an opening paragraph for an essay question.
Write an essay on Macbeth, focusing on conflict.
A play in which a central character experiences both inner conflict and conflict with other characters is Macbeth by William Shakespeare. Macbeth’s inner conflict arises from his desire to kill Duncan, King of Scotland, and seize the throne for himself - an ambition that his conscience tells him is wrong. This conflict is the key to Macbeth’s character development and it leads him to clash with other characters, notably Macduff, with whom he fights in the play’s dramatic conclusion.
Ensure you make frequent links back to the key phrases from the question, not only in the introduction, but also in topic sentences at the start of paragraphs.
The importance of Macbeth’s inner conflict to the development of his character becomes clear in his soliloquy in Act One Scene Seven.
The main body of the essay should be developed with both statements and evidence.
Many people recommend the PEER structure: