If you research the institution before the phone interview, you'll get an idea of which areas you should stress. Look at the institutional and departmental Web sites. When the interview is scheduled, it's fine to ask who the interviewers will be. If you are given names, you can do some research to learn a bit about their backgrounds and, therefore, possible interests. You can have notes in front of you, take notes while other people speak, and wear what you choose.
Some people enjoy the luxury of interviewing in their pajamas.
Others have told us they find it helps to dress up for a phone interview. The choice is yours. Be sure you won't be interrupted and that you are in a quiet environment where you can concentrate on the interviewers' questions and comments. Have any notes you want, as well as note-taking materials, handy. If before the interview you've printed out departmental information from the institution's Web site, you can quickly identify faculty members as they introduce themselves over the phone.