How should I use quotes in an essay?

Common methods of quote analysis taught for GCSE-standard essays are similar to PQA (point, quote, analysis), which can be effective - if formulaic. While this works well at lower levels, variation can be key to improving your writing style and argumentative rigour when writing for A-Level standard and above.

PQA ought to be adopted if the quote being used drives your argument forwards, and if analysis of the quotation is key to understanding what is being said. The quotation need only be set apart from the rest of the paragraph (set a line under and a line above surrounding text, and indented) if it is substantially long - common sense should be used, but people commonly indent if the quotation would take up more than three indented lines. 

If a quote is being used to support a point or assumption (for example, summarising a character's personality or setting a scene) integration can be useful, showing your familarity with the text while continuing to move your argument forwards. For example: 'The 'serpentine' path described at the beginning of Stoker's text...', 'Although 'dressed in white', the protagonist...'.

Quotations need not be taken solely from primary texts - critical quotes can also show a high level of engagement and understanding. Critical arguments and quotes should be used to forward your argument, not merely support it. Whether you agree or disagree, your opinion should be supported with references to the primary text, and each critical quote should be employed with purpose. A particularly good approach is to compare two critics who hold conflicting stances, explaining who you support and why.

It can be difficult to know what method is the correct one to employ at any given time - I would reccomend googling some of the themes and texts you're writing on, and reading relevant essays on 'google scholar', and passages from books on 'google books'. From these, you can not only gain more insight into your texts, but also begin to pick up on different ways to employ quotations.