Since a telephone interview is generally a test to make it to the next round, be prepared for a phone interview as an interview with one in person. It means do all research about the company or organization as well as the people who speak with during the call.
Really, there are lots of facts showing that how the dress affects the work. So, when tempted to do the call in your pajamas, take it up a notch.
Control the atmosphere as much as possible where you take the call without disturbing noises.
Telephone interviews are not an ideal way to show the multitasking abilities. Close all the windows on computer, except something which want to reference - like profile or the web site of the organization interviewing with. Close email and without doubt don't eat, drink, chew gum or do anything else that would obstruct the speech or create disturbance. Avoid using a cell phone, because calls can get dropped and disable call-waiting if that service is available.
Have a friend call you and see how you sound. Ask whether you sound better while standing or sitting. Some people sound much more relaxed when standing, or even pacing. So do as comfort when taking an important call.
If possible, get the names in advance of who will be on the call and know what their roles are. If there is more than one person on the call and not able to distinguish their voices, ask them to identify themselves the first few times they speak.