Working from home for many years, here's my take:
* Discipline to start your day, but also to end it.
* You need to dedicate an area to be your office and come and leave it as if you had to commute to work.
* Go out and socialize! Especially for introverts, it's easy for us to neglect some social balance.
* At the end of the day, make sure you switch into activities which will 'switch' you off work and into something else (working out? Hobby? Kids homework?)