Sometimes when you get caught up working on the same project for an extended period, it could weaken your creativity. Your day could get even worse if you forget to look up at the sky every once in a while, telling yourself to get up and walk around outside for some fresh air sometime.
Your body always appreciates some exercise after lunch and your mind as well.
You just got to finish your meal fast and sketch faster...
here is some sketch I did with pen and ink in just about 20 mins during my lunch hour, and the result is strangely satisfying!
