Selecting appropriate activity to fill time. Only have a few minutes before bed? Here's some laundry I should fold. Oh, hey. MY friend left a new comic for me to read. Guess I'll breeze through that. Its 9 am and I don't work until 2. I think I'll go for a bike ride, maybe pick up some brewing supplies or groceries or some thing. Maybe even hang with a friend on their lunch hour.
Keeping Momentum. The Devil makes use of idle hands. Once your initial activity is complete, repeat steps 1 and 2.
For Weekends/ Days Off. I have a philosophy. Get all of my household and personal chores done on days I have to work. That way, my days off are 100% free time. Which basically means hiking or biking with friends. Maybe even going out and being social somewhere. Or finishing personal projects like recording some music or drinking coke (that's just me, maybe you want to finish that painting or build some wooden furniture). Just have a healthy mix of constructive and social activities in mind to occupy yourself.
When you do stuff, your mind can't focus on negative stuff because it's too focused on "My water is at striking temperature, pour it into the mash and sparge the wort!" Or "This is a 30 foot putt, better bring out my Buzzz." or "Oh shit! Jon Snow just (spoilers)." That sort of business.