At my job you have clients calling you emailing, and walk ups. And that is multitasking to the extreme. My task is when i am on the phone,gesture to the client walking up that yes you see them, and will help them as soon as possible. Emails. Just email back that you received there email and will help them as soon as possible. And by 5. RUN for the door. So phone call tips. Don't leave your customers, clients, or whom ever calling you, hanging. Later.