"Don't be fooled by the calendar. There are only as many days in the year as you make use of. One woman gets only a week's value out of a year while another gets a full year's value out of a week." Charles Richards
Our personalities, personal preferences, and our specific strengths require that each of us understand what works best for us in terms of getting organized.
A simplified example is that the linear thinker is content with doing one thing at a time, the visual person will want to be able to see what needs to be done, and the creative type enjoys thinking and doing a number of things all overlapping. To work effectively, we need to understand what works for us.
Technology has helped in many ways but it has also overloaded us. We know that if we don't prioritize our activities, we find ourselves spread so thin that we won't have time for those things that are important to us.
Whatever system you choose to use, whether personal or professional, begin each year going through and highlighting all recurring events on your calendar. Schedule your "think times" and also your "catch-up times." Use your calendar for follow-ups, tracking projects, or list the names of people to contact, etc.