It helps a lot of people when there is a separate workspace at home (not a kitchen table after breakfast). Sitting in a workplace is like getting to the office. For some people, even office clothes or makeup help.
That doesn't mean you have to wear a jacket and tie. It means you need to understand what creates a work atmosphere for you. If you need Pink Floyd or RHCP for your work mood, turn on the music. The main thing is that external factors should help you switch between "work" and "home" modes.
If you are using the same computer for work and the rest life, it may be useful to split it into two accounts. Then you will be less tempted to check your personal email or Facebook.