Most students at GCSE are taught to use the structure of PEE (Point Evidence Explanation) in each of their paragraphs in order to construct their argument. However, A-level requirements differ, as examiners want to read an interesting, discursive essay. Below are some tips on how to maintain an efficient structure which gets your point across, while also allowing your essay to come across as unique to the reader.

Practise discussing your ideas aloud. This may sound like a peculiar first tip, but it is essential that you can articulate your ideas and speaking aloud lets you find your argument with your own voice. PEE paragraphs come across as robotic, but discursive essays act like an internal conversation that you are having with yourself over the set text. 

Adapt the structure you already know. PEE has likely been your backbone throughout your academic life and there is a reason for that. Think of each paragraphs as your building blocks, with your whole essay being the finished building. This is why each paragraph must have a point, which ties to the whole of the essay. However, your use of evidence can vary. Use more than one quotation, spread them throughout your paragraph linking each of them together. This still uses PEE for a basic foundation, but allows you to draw more complex ties with different parts of the novel/poem that you're looking at.

Lastly, don't forget that there is a way to be formal and have your own voice simultaneously. The more you practise talking about your ideas and playing with paragraph structure, the more you will find what you are comfortable with and works for you. Every one has an 'essay' voice and an every day voice, and often the best essays are those which find where both of those voices merge.