This one's big.
Lets see you've got some seriously addictive habit, a way you want to compulsively waste time. Maybe online, or otherwise.
Maybe you've tried to quit, and haven't been successful, or maybe you wouldn't mind if you indulged a reasonable amount of time (say, an hour a day max?)...
..and that's fine, except sometimes you'll click over to your habit and burn 3 hours, or 5 hours, or worse.
I know I've done it. And maybe you have too, whether it's compulsively purposelessly checking stocks and financials even if you don't have any real cash to invest right now, or getting stuck on online Chess or a strategy game, or click-click-clicking through Hacker News or Reddit and repeatedly refreshing, or -- perhaps worst of all -- geting in a click circuit fo all your favorite news and social media accounts... endlessly.
Is there an answer?
I think so!
Only do one of those tasks when you've got a hard commitment in an hour or less.
The danger of getting sucked into reading a news site isn't that the news will kill ya... it's that 5 hours of mindlessly zombie-reading the news will kill ya.
Of course, before you do this, finish your preparations. Get your work materials out, write an agenda if it's a meeting or call, or otherwise be ready to start. Then set an alarm for 5 minutes before the event if you're worried about missing it, and then indulge... and then off to indulge with a greatly lessened chance of damage.
(Or you could just do SelfControl Always On...)