Choose your topic wisely. Pick a subject that has gaps in the research or that can be researched in a new way. You should choose a topic in which you are interested to ensure that you will not lose interest in the thesis before you even begin to prepare your thesis defense.
Research the defense process at your school. The main key to defense preparation is to find out as much as you can about the process your school uses. The school of graduate studies, or equivalent administrative body, usually predetermines guidelines for defenses. Some schools require the student to make a presentation, whereas others simply ask questions about your thesis. Ask your tutor to fill you in on the defense requirements at your school to ensure that you are fully prepared.
Join a community that has frequent get-togethers so that you can discuss your thesis with your peers. This will help you to solve any issues with your research and help you to feel comfortable when discussing your ideas in front of other people. Set up a practice run in which you and some friends each have to defend your thesis in the same format as a defense committee. Ask your peers to question you on your topic to help you prepare for the real thing.
Make sure that each committee member has received a final copy of your thesis at least a few days before your defense. This will allow them enough time to read through your thesis ahead of time.
Be passionate about your thesis. You have chosen this topic, so you should have a large amount of knowledge about what you are talking about. The committee members will be more likely to engage in what you are talking about if you are passionate about the topic yourself.
Try to relax. By the time you present your thesis to the defense committee, you should already be an expert in your particular topic area. You should be well prepared to answer any challenges that the committee might present, so try to stay calm. It is normal to be nervous; however, stress might interfere with your presentation pitch, so practice breathing exercises to keep calm throughout.