Writing dissertation can be something very difficult if it is of your first time. On thing you should consider is keeping your style formal and it should be identical to what you see in the journals of you criteria of field of knowledge.  For simplicity, you would have to take a look at some of the articles in your field of knowledge so as to observe what to expect for example, the language, structure and style.  Reading current journals of your field will also be of great advantage.

Try to keep it simple: The literature review should be written in the most academic and formal language.  Try to make your sentences short and less complex.

Remain Unbiased:  Try by all means to maintain a scholarly tone, respectful when pointing out work which has been done by others. This is one of the qualities you should keep in mind.

Write for a Wide Audience: Try to make it understandable even to those people who do not know anything about the field. You should write it in a way such that it caters for everyone and not targeting the people in that field of knowledge only.

Use Active Verbs: Make sure that you use active verbs so that the writing does not become deadly to read. For instance using passive verbs like has, is, was, had, have. The use of passive verbs would make you include so many words that are unnecessary to say the same thing.

Keep Key Words and phrases Handy: Try to scatter the keywords throughout the document. Hence, it would be very important for you to list the keywords and phrases which are essential in the document.  

The main key to a successful well written dissertation is practice. The more you practice the better you become.