How can I help boost my marks in my speaking exams?

Firstly I would have a short conversation in mandarin with the student in order to gage where their speaking level is at, as I understand each student will not be at the same level. If the student's speaking skills are not so good then I would suggest to them to get more familiar with the content on the syllabus rather than attempting to use vocabulary that is too advanced, as this would only lead to confusion and misunderstanding. I would dedicate a section of the lesson to speak Chinese with the student in order to improve their confidence.If the student's speaking level is competent, I would suggest using more advanced vocabulary. I would advise against using large amounts of vocabulary that they are not already familiar with, as this will be difficult to memorise, and words that are too specific cannot be used in multiple contexts. But using a few more complex words and phrases here and there will get better marks and is not too difficult to implement.The best way I would suggest doing this is by using different sentence structures, which will not only improve the students' vocabulary and impress the examiner, but also make their speaking more fluent and sophisticated. I would go through with them words and structures they can use, then help them to understand how to use them by getting them to make up their own sentences. After they are more familiar with them we can speak together in Chinese using the sentence structures and words learnt to solidify their understanding.