One east coast executive of a large printing company repeatedly amazed me at how he never forgot anything. His secret? He kept everything in one notebook and crossed off items as he completed them. He always knew what he did, what he was doing, and what he was going to do. He occasionally looked tired, but never stressed.
Underschedule Your Day
There will always be things--often important things--that will of necessity intrude. Give your day some flex. And keep in mind people are more important than things. In other words, give time and attention to people who want to talk with you. We win or lose with our people. If they are the most important than we need to conduct ourselves accordingly.
Watch the Phone
Most phone conversations are too long. If you have a time counter on your phone, use it. When you begin a conversation, note how long you think you will talk. Then check it at the end. You will consistently be amazed how far over you go. All the time. Use phrases at the outset of conversations such as, "I'm under a time gun, but I do have a minute or two..." "I've only got a minute but I really wanted to talk with you." If you use them at the frontend you will not offend by closing things down when you have completed the purpose of the call.
Get rid of all paper, records, files, etc., that litter your workspace and you really do not need. It's presence is pulling your attention away from more critical tasks. Sort your mail and email once, ruthlessly. Toss out stuff you know you will likely not respond to. Don't let it pile up. Speedread the stuff in your in-basket. Don't pour over it. Skim and decide.
There's lots more to time management. But I’m out of time. See you next month.