My first question for you is what are you doing all day? Do you have applications like Facebook, Twitter, games or even email open all day? These can suck you and take your productivity down to 0. I would recommend shutting them down including your email and working on other projects. You may be wondering about email, but I will explain.
Email is a time waster as you either get a lot of messages or you get none. If you get none and you keep hitting the refresh button, you are wasting time. If you get a lot, chances are you are pouncing on each one when it comes in to deal with it. This wastes a lot of time as you lose productivity switching from task to task.
What I recommend: turn off you email and only check it every hour or two. You will be more focused and resolve more issues when doing this. I have done this myself and found it definitely made a difference!
A to do list and a timer are your friend. Make a list of what you want to accomplish that day and approximately how long it will take. Set the timer and off you go! If you have time leftover, start the next task. You could end up with spare time at the end of the day and then you can play.
If you take a break to check Facebook or other items, set your time for this too and stop when it goes off. These can suck you in and two hours will go by without you noticing.