It is very important to elaborate on your evaluation.
Next conduct preliminary reading based on your lecture notes.
At this stage it's not crucial to have a robust understanding of key theories or studies, but you should at least have a general 'gist' of the literature. This plan could be in the form of a mind map, a summary table, or by writing a core statement (which encompass the entire argument of your essay in just a few sentences).
(Point) It is argued that psychoanalytic therapy is only of benefit to an articulate, intelligent, affluent minority.
(Explain) Because psychoanalytic therapy involves talking and gaining insight, and is costly and time-consuming, it is argued that it is only of benefit to an articulate, intelligent, affluent minority.
It would be useful at the beginning of each paragraph if you explicitly outlined the theme being discussed (.e.g. Psychology is a science so you must support your ideas with evidence (not your own personal opinion).
If you are discussing a theory or research study make sure you cite the source of the information.
Rather than hunting for weaknesses in every study; only highlight limitations which make you doubt the conclusions that the authors have drawn – e.g.
where an alternative explanation might be equally likely because something hasn’t been adequately controlled.
If there is a word count for your essay try to devote 10% of this to your introduction.
Ideally the introduction should; Introductions are very important as first impressions count and they can create a halo effect in the mind of the lecturer grading your essay.