An important aspect of fostering boredom is avoiding gratification like Netflix or Twitter (which I am hugely guilty of).
Keep in mind, dopamine isn't a "pleasure hormone". It's a reward anticipation hormone, one that drives you to do painful things for a reward that might not happen. It mixes both excitement and anxiety... excitement to get you started, anxiety to force you to finish.
It doesn't trigger in things that are actually relaxing. That's why people who are actually having fun 'procrastinate' less on some sites.