Also, I'm not good at focusing in the design / planning stage, if the new feature is kind of ambiguous, and I'm not exactly sure about the requirements. I think it'd help a lot if I had some clear strategy about the design process. Sometimes, though, not actively thinking about something let's the brain sort everything out, and the right solution kind of emerges on it's own.
Currently I'm working on a task 'design and implement the billing system', so here I am on HN.
Edit: I also use https://heyfocus.com/ which bounces me back to work, if I 'accidentally' drift off.