How can you best support a point being made when analysing writing?

Analysing a text is something that can take some practice. The first thing that is important is to choose which evidence you would like to use to support what you're saying. You can quote the text to help demonstrate the point you're making, and be specific about it. Try to avoid using overly long quotes unless it is necessary to make your point. Using a short, but effective quote will better showcase your knowledge as it shows that you understand the devices that are being used.
Wherever possible, you should use appropriate terminology for what you are saying. If you want to say that a text addresses a reader directly, you could say "the writer uses the pronoun 'you' to address and engage the reader," as this shows your understanding and embeds your language knowledge in your analysis. Remember Point, Evidence, Explanation (P.E.E) so that you're fully supporting your points throughout. Importantly, practicing pulling out your quotes and analysing them will make it easier to do when it comes to sitting the exam with an unfamiliar text.