What do others do when waiting for their compilers to complete?
* Stand up/walk a couple of meters
* get a cup of tee
* use the pull-up bar (well, we have one in our office)
You get the gist - do something for your body/metabolism. Even if it's just a little - these add up, improving qol down the road
Codepen and Dribbble are nice too, just browse around looking at art and look like you're working. It beats news sites in that you can discover a new, useful thing.
Also you can meditate. Maintain concentration for 2 mins straight. It's not hard, and helps you regain composure.