It's very easy to become too involved with your own ideas, and forget that how they fit together might not be obvious to someone else, so it is a good idea to take time to think about the needs of your reader. The more acurately you can imagine your audience, the better adapted your essay will be to its rhetorical situation, and the more likely it will be to get good marks, provided basics such as referencing and a bibliography have been taken care of.
Considering the issue of reader's cues is important at this stage, and should lead naturally into beginning to write the text of the essay, as one of the most important cues is the introduction. To make sure that your reader recognizes the context of your argument, you need to think about how to relate what you're saying to key issues in the academic field - you should have already worked out what the relevant ones are by thinking about the question.
As you write the essay, you need constantly to consider whether you are producing reader-orientated prose. The notes and plans you are working from are writer-orientated, in that they take for granted the mental picture you have already formed of the topic. But the reader doesn't already have this mental picture in their head, so you need to provide help for your reader in the form of cues and explicit structure.