Prepare well for a telephonic interview
Since the telephonic interview is mainly preliminary in nature, you can expect not to be asked any questions of a technical nature - that will in all probability be saved for the main interview. Right now, the focus is on gauging your communication skills. So do your homework. There are always going to be questions that will be unexpected. You need to be prepared for those. Keep some important documents and a pen and paper handy in case you need to either refer to some notes or write down something that is important.
Asking for time to get that pen and paper during the interview itself will only convey the impression that you aren't fully prepared. Ensure that you gather relevant information about the company, so you are able to prove to your interviewer that you are genuinely interested in joining.
Once the interview starts, it is all about you and your approach. While answering questions, be articulate and clear as you speak. Avoid long pauses. Answer every question to the point.
Avoid using words you don't know or can't pronounce. Simple language can never spoil your chances. The thing that matters is what you are saying and how you are saying it.