1) Keep a daily log of your "to do list".
2) Make the most difficult task on the list your number one thing to do,the second most difficult thing, your number two, and preceed accordingly.
3) When you check your emails, highlight the ones you may want to take a closser look at, and delete the others. Don't spend too much time with the emails because it can get you sidetracked.
4)Answer the important emails right away in addition to answering all of your import phone calls.
5) Multitask when possible. For example, you may be able to make copies of somethings you need, and clear off your desk while the printer is making your copies.
6) Make the last thing you were working on at the end of the day, your first thing on your to do list for the next day unless something comes up more important.
Well those are the tactics I use to manage time effectively, and cut down on stress. I hope I've been of some help to you.