In order to achieve success in the speaking test I suggest the following:

1. Understand the four grading criteria of the test:

https://www.ieltsanswers.com/speaking-grading.html

2. Make sure you understand what is required in each part of the speaking test, by looking at sample questions:

https://www.ieltsanswers.com/speaking-part-2-questions.html

https://www.ieltsanswers.com/speaking-part-3-common-topics.html

https://www.ieltsanswers.com/speaking-part-1-sample-questions.html

3. Build strategies to give extended answers

https://www.ieltsanswers.com/speaking-strategies.html

4. Build vocabulary

https://www.ieltsanswers.com/speaking-vocabulary.html

5. Have a mock test to get an idea of your score and to get suggestions about how to increase it https://www.ieltsanswers.com/skype-speaking.html