An essay only hits the mark with its readers if it is good enough to satiate their intellectual or academic appetite. Thankfully, it is not tough for this form of writing to enter into the psyche of those reading it because it has a composite style, a strong skeleton and a large number of techniques to fall back upon.
You can go with the traditional style of framing your piece with an introduction, a body (spread out in neat paragraphs each leading to the next) and a conclusion. If you want to be in sync with the present times, you can subtly put a call to action, too.
You can also choose the much coveted style of bulleting or numbering your points. The attention span of readers today is nowhere close to what it used to be and some of us- I am sure we will agree- do not feel the urge to go through lengthy paragraphs. Points mentioned in bullets or numbers divide the paragraphs into easy take-home ideas. Just what the doctor orders!
This particular form of writing is all-encompassing in nature; be it its scope or its form. You can approach it in an opinion-oriented form, too. This way, you will be travelling the subjective way of approaching a topic and end up giving your views on the subject. Such pieces have the liberty of cutting down on stats and facts but are rather well covered when it comes to stating an elaborate opinion on a particular subject.
The bipolar opposite of opinion-oriented dissertation is the data-centric piece where you piggyback on hard core stats and data. Here, opinions and subjective study can be interspersed but stats pretty much call the shots.
You can also cultivate the ground of your essay with the help of some literary device. This approach is more suited to the literary or the academic kind of dissertations. You can indulge in creative liberties; use stream of consciousness, meta-fiction, delayed decoding and dense narrative structures, medias res technique and so on. None of them lend themselves directly to this genre but you can play with any of the above ideas and mould them into this old and time-tested writing form.
Whichever way you choose to progress with it, remember at all times to stick to one single approach and follow the thread till the end. There is a good chance that if your subject matter is strong and your writing is a work of art, you will boot home the point and in quite a style!