Simply switching devices helps. If it's after 5pm and I don't have any meetings or tasks that I can complete by 6pm, I turn off the work laptop and put it away until the next morning.
That's so true. It sucks a bit when you develop a lot of 'online' hobbies, like gaming, reading blogs, etc. But backpains will make even the most hardcore games into runners :)
Getting off devices entirely is even better.