Always try to answer your phone within 3 rings. Answering way to fast can catch the caller off gaurd, and taking forever to answer makes the caller angry.
Always end with a pleasantry such as : "Have a nice day" or "It was nice speaking with you."
Don't answer your phone while meeting with others.
Don't place your phone on the table while at dinner or while having a meeting.
Let others know when you have them on speaker phone.
Be aware of your speaking volume.
Don't leave long long voicemails.
Listen actively and listen to others without interrupting.
Using phrases such as "thank you" and "please" are essential in displaying a professional atmosphere.