As interruptions are productivity killers, the biggest offenders are the so-called time-wasters. These are activities that have none to almost no benefit to your work, productivity or even psyche and can be cut out of your life without consequences.
If the time waster is a bad habit, try to increase the friction of the habit.
Reference
Ferriss, Timothy. The 4-Hour Workweek: Escape 9-5, Live Anywhere, and Join the New Rich. Expanded and Updated ed., 1st revised ed, Crown Publishers, 2009.
Highlights or timestamps
You should especially be on the lookout for interruptions – things that prevent you from completing important tasks, from start to finish, without pause. Perhaps the most costly kind of interruptions are time wasters. A time waster is any task that you can ignore without negative ramifications.
— ^9d4cac from The 4-Hour Workweek