It's easy to get caught in rehashing the past or rehearsing the future and miss out on the fullness of this present moment.
Practice being present with each activity, person, sensation and emotion that comes before you. Try an easy meditation technique such as focusing on your breath, your thoughts or some internal physical sensation for a few minutes as a way to connect to the power of the present moment.
Remember, you can't do anything about what's happened in the past and you can't control the future. Feeling stress over either the past or the future is wasted energy. You can control only what happens in the present moment. Release all the other and focus on what's happening now.