Can you explain to me how to construct a good essay?

The key thing with writing a good essay is coming up with a strong thesis. When examiners mark your paper they generally look for a sense of clarity and a strong line of argument. You are usually given a specific viewpoint in the question and you can choose to either agree or disagree with this given view. However, your argument should stick to that thesis throughout the paragraph and throughout the essay, try to avoid being tangential. Once you have decided what your view is you must select the key language and structural features to the piece of literature you are analysing and find the ways that these examples support your argument. Then you should try and include any way that these language features are products of that particular writer and the time they are writing in. You can also pick out any critical quotations you have memorised that will accompany your point. All these features play in to the key marking descriptors for higher bands and therefore higher-grade answers.
Try to break the essay down while you’re planning it. Think of your paragraph like a floor of a building that you are slowly constructing. In building you should always have key constructive materials like bricks and mortar. Think of all the elements you need to include as these materials so they become easier to remember and so that you also begin to view them central components. For example, a building wouldn’t look right without windows in the same way an essay wouldn’t read well without accompanying quotations to back up your argument. The exception to this is the introduction and the conclusion. You could think of these paragraphs as being a foundation and a roof to your building. They do not necessarily need to include all the same key elements but they still need to be structurally sound in order for your essay to be fluid and make sense.