There is resistance among some students, and some academics, to transparent and straightforward structure and signposting in essays. A lot of people think that an essay starting e.g. 'In this essay I will be making three points...' is a childish or unstylish essay. I disagree. I think an essay that says at the outset what points will be made, makes them, summarises the case and provides a conclusion – with each new stage in the essay signposted – is a clear essay. I have never read an essay and thought to myself, 'This is dreadful – it's just too clear' or, 'This is a good essay, but I just wish the arguments weren't so lucidly signposted'. A clear essay is a good essay; and explicit structure and signposting, I believe, are among the most effective ways to make your essay clear and your arguments transparent.
If you think of your essay as being a stretch of terrain, one of your duties as a writer is to provide your readers with a map of the terrain, and signposts to facilitate their journey through it. Your introduction should include a basic map. It is also a good idea to include several transitional sentences in the course of your essay that act as signposts, telling readers where they have got to and how far they still have to go, e.g. 'A second argument against mind-body dualism is ...'; 'Moving on to the question of free will, ...'; 'To summarise the historical evidence: ...'. Without a map and signposts, travellers through your essay are likely to get lost and disoriented.
Each paragraph should make just one point, or sub-point, or at least have a single clear theme, which is illustrated with a couple of examples and/or quotations. As a general rule paragraphs should not be longer than about a third of a page. They can be much shorter if the point is a short and snappy one. It is often a good idea to start a paragraph with a transitional sentence or with a sentence stating the topic of that paragraph.
There is no strict rule about how long supervision essays should be. As a rough guide anything between 2,000 and 2,500 words is normally acceptable. Fewer than 2,000 words would not normally be enough to show evidence of a substantial amount of reading, noting, and thinking. An essay of more than 2,500 words might sometimes be acceptable but it may be that you would do better to spend some more time reading and thinking and to produce an essay that is strong on analysis and quality rather than on sheer quantity. It is also worth bearing in mind that one of the main purposes of supervision essays is to develop skills that will be of use in your exams, when you will only have time to write 1,000-1,200 words at the most for each essay. This does not mean that supervision essays should be as short as exam essays – they should not – but it does mean that it is important to learn how to be selective and concise when planning and writing your supervision essays.