Before starting, make sure you choose and write down 2 (only 2!) options of high value for the day. Don't further analyse your to-do list without completing at least something in both.
Of course your day will be full of "fires" that you'll have to deal with immediately. The important is: when you come back from the fire, what do you do? This trick is: while you still have the 2-options-guide to deal with, don't go and check the e-mail or reassess your to-do list. The choice has been made. Trust it. Respect it. Look for blockings if you feel you are avoiding the task.
This TRICK is really valuable and useful! It gives me direction throughout the day and helps me avoiding distractions! Whenever I make my "guide for the day", I stick to it and accomplish it my day is truly rewarding, so when I leave work I usually have a big smile! This helps a ton to make my Great Days!