I would add: "Listen to other people on set". Sometime others have good ideas, or sometime you are wrong and other people are willing to correct you. Keep your mind open to suggestion coming from others, altough final decision is yours. It can save your time, save your team self estime, save your own image as director, and maybe even save your film :-)
Simple and clever! However the "marking the good take" trick appears not so necessary at the end: most of the time, the good take is just the last one!