Just started using LeechBlock on Firefox to deal with procrastination. Settings attached. Basically, I allow myself an hour of browsing the listed websites between 8pm-midnight, Sun-Fri, except checking notifications from these websites. The other screenshot is what you see when a URL is blocked.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko