Some tips that can be effective for new dissertation writers:
Dissertation writing needs understanding of the topic or subject. So, choose the topic which is clearer to you.
Dissertation writing needs planning and research. So, plan well before you start writing.
Keep your grip tight on the selected topic.
Discussions, observations and opinions should be analysed and evaluated decisively.
Dissertation writing is a show case of your abilities and skills, so prove your thesis by mentopning solid evidences and arguments in your dissertation.
Use appropriate references.