In part 3 of the speaking test, you should try to give longer, detailed answers. A good way to do this is to imagine that you are making a paragraph.
Remember the 'paragraph building' techniques that we use in writing task 2:
Idea, explain, example
Start with a direct answer to the question, like the 'topic sentence' in a written paragraph. Then explain your answer in more detail, and support your explanation with an example.
Try answering this question: Do you think that it's important for people to go on holiday?
Firstly, secondly, finally
Start with the direct answer, then explain it by giving two or three reasons, and maybe an example too.
Try answering this question: Why do you think some people prefer not to go abroad on holiday?