Got this idea from the Mindvalley content - Being Indistractable by Nir Eyal
Distraction is anything that takes away from your traction or planned work.
Distraction could be useful work but its a distraction since it is not scheduled
If you have no schedule then distraction does not make sense. Distraction should be against a schedule so rule number 1 is schedule your day then only you will know how much you are distracted.
10 Minute Rule:
If you have an urge for distraction like checking facebook just set a 10 min alarm. You are delaying the urge by 10 minutes. Observe how you feel. Its perfectly ok to go to your urge after 10 mins but most probably will not.