I know that a dissertation/thesis format is an important requirement, which your work has to meet. Yet, I would not advise you to start working on your paper with a dissertation/thesis format. You will always have time to fit your writing to a certain format. All those manuals on the dissertation/thesis format can be easily found, and you will be aware of all the requirements.

I am sure that your main concern should be focused on the subject of work. If you want to get a good piece of writing, you have to feel the subject. Your topic should be closely connected with you. It should be a part of your inner world. Only in that case you will be able to work productively.

How can you understand that your topic fits you best? There are several methods to define it.

First, you need to find a quiet place and sufficient amount of time for thinking over thoroughly every aspect of your topic.

Then you have to think of the feelings that the topic arouses. Needless to say, these feelings should be positive. If you feel that some points of the topic make you feel depressed or just uncomfortable, it is better to think of another topic.

Think whether you have some memories or experience in your life connected with your topic. It will be much easier to disclose it, if you once you have dealt with a similar kind of work.

Because of all these peculiarities, choosing a topic is called one of the most difficult parts of writing a dissertation/thesis. Yet, if you want your work to be successful, you cannot omit these specific aspects.