What is the best way to write an introduction for an essay?

An introduction is arguably the most important part of an essay, as it lays the foundation for the rest of the paragraphs to come. As a result, introductions should be clear and concise. The first sentence of the introduction should answer the essay question, sometimes repeating the same language to assure the answer is focused. For example, if the question is asking about the role of women in Frankenstein, the first sentence would often look something like 'In Mary Shelley's Frankenstein, the role of women is explored by Shelley to...'. The following sentences should present the themes or "strands" of the essay, covering points of the main argument. For example, 'Women are presented as commodities, subservient to men, and their role as mothers is diminished through science.' Lastly, the concluding sentence of the introduction should sum up these strands in an overarching thesis which the essay will explore, an example of which is 'Therefore, Mary Shelley uses the role of women in Frankenstein to critique...' and etc.
Through this 3 step method, the introduction acts as a backbone for the rest of the essay to come. This allows you to convey your overall argument concisely and enables you to refer back to it in future paragraphs for guidance.