Before you confirm an interview time, make sure that you are going to be in a suitable environment where you wont be disturbed and also if you are using a mobile, try to be in an area with good reception.

Have a copy of the job description or advert to hand and cross reference points from your CV.

People always respond to interest about their products and business, so it is important to do your home work on the company and also during the call have information available to you from their website or LinkedIn page.