Students find it incredibly hard to choose a thesis topic. This is perhaps a challenging experience during the beginning of your thesis career. Choosing the right topic is beyond straightforward, causing students to get unduly anxious about the whole process. But rest assured, a good attitude and a good strategy can help you with merging your ideas with the thesis topic of your choice.
You really want to choose a topic that you are really passionate about. PhD is a challenging academic experience; in that case, you stick to something that you are already passionate about for your thesis. Besides that, you will research on that topic for the next 4 to 5 years of your life, and start to build your career as an independent researcher.
Try not to make your thesis into an over ambitious project. Gather all your ideas and form one central research question. Then lay out the plan that will help you answer key questions about the central idea. In order to come up with a unique idea, you must research on existing idea. The best way is to read journals on that topic. Find out what has already been done in the field, what has already been published? The next goal is to identify some fresh ideas or questions that have so far remained unanswered. You will get a well-rounded perspective once you have considered different ideas. When you are looking at several different ideas, it will help you understand which idea you genuinely wish to pursue.
You also want to make sure that no one had the same ideas as you in the past. You must check for published research papers that may have the same central theme as your thesis topic. Additionally, you will also have to answer why is your thesis topic relevant. What is new and unique about it? Why must the scientific community care and why must it get published? Once you have satisfactorily answered those questions you are ready to proceed with your thesis. Additionally, you must find arguments or references to support your ideas.
It is not unusual to doubt the relevance of your chosen topic. In that case be patient, and have faith in the efforts you have put so far. If you have extensively researched on your ideas then it is most probably unique. You can also seek help from your thesis advisor, thesis committee members or your peers.