We're big fans of using paper as a productivity tool—task lists in particular. The best tool is whatever works for you, and for some people, that means paper. It's just more tangible than a to-do list app. A simple way to make paper task lists more effective was discovered by Keren Kinberg, a frontend engineer at Zapier, who began highlighting completed tasks instead of crossing them out. This change provides an odd satisfaction and makes it easier to see what is left to do. Additionally, this method has benefits that go beyond just productivity, such as giving someone an excuse to buy new office stationery.