1. Be a confident version of yourself.Typical questions for phone interviews are the classic "tell me a little about yourself", "tell me about some science you've done" or "what is your favorite animal?" (kidding)
2. Go over all the documents you've given them, be familiar with them.
3. Do some research on the people you've been talking to. (SciFinder searches are helpful for that.)
4. Find a private, quiet place to have the conversation.
5. Use a landline.
Readers, any other tips?
UPDATE: See Arr Oh has great advice; I like his idea of a "gap analysis." I also like SJ's thoughts in the comments.
UPDATE 2: The correspondent notes that it's important to get time zones correct. Makes sense.