A great way to do this is to record your IELTS practice speaking interviews, then transcribe what you have said and identify mistakes using grammar check software.
If you can give good answers to the questions in part one, hopefully that will build your confidence and you'll feel more comfortable speaking in the exam.
Even in IELTS listening, you will have a dialogue between students which is more casual, a lecture which is more formal and you will have a face-to-face interview with an examiner in IELTS speaking.
Because my finals exams are such a shambles that the examiners they settled me in for a " Viva" , and they told me that if I go up a second... - What's a " Viva" ?