1. Film making is a collaborative process, you have to work with other people to make it happen. The best part about making movies is that you get to work with a bunch of different people. The worst part about making movies is that you have to work with a bunch of different people. So to be a successful film maker you need to learn how to work with people. These "soft skills" are often very difficult to learn for artistic people. We always have so many ideas, and we are sure our ideas are the best. So when you get a group of creative people together, there could be a lot of arguments about how things should be done. Film is written three times, when you write it, when you shoot it, and when you edit it. If you want to be able to write a script that nobody changes, become a poet. In film, it gets changed all the time.
2. Director should empower people. Give the people on your team a say in the creative process of film production. Don't just order them around. Great ideas come from everywhere. And when you allow people to have a say in the process, it gets them more involved in the film, and would prompt them to come back again. Listen to people around you and take advice. If you're a new director, people will instantly know you don't know what you're talking about. So be transparent, and take advice from others. Don't be afraid to hire very experienced people and than learn from them.
3. Art is only a part of the film process. There is also a lot of management that needs to be done. You have to keep track of all the people around you. And you have to keep track of time to minimize costs.
4. Pick out people for every role that come to have a great time, rather than been obnoxious or scream at everybody. It will show up on the screen and everybody will want to come to work every day. You might still get momentary flare ups from time to time, because it's a creative environment, but it will be over quickly, rather than been a constant dread on the team.
5. Long filming hours require a sense of humor from somebody. When the tension builds up, it's so great to have a laugh to lighten it up.
Sources:
"The Essentials of Film Directing", http://www.youtube.com/watch?v=ZdzzK9kf3cg, Published on Dec 19, 2012