You need to return several phone calls throughout the day. Concentrate on your most important projects and group all your calls for one time period. Don’t break concentration by jumping back and forth between tasks and then repeating the same task over again later. If possible, set up, carry out and follow through once for greater effectiveness.
This is where substantial amounts of time can be gained. It will take a disciplined approach, and you may need to train your support staff in your improved methods. Over time this new efficiency will reap big rewards.