The golden rule of moviemaking is communication. Share information as much as possible and be ahead of potential problems. This includes making sure you are communicating with the financing parties of your movie. Your financing may be made up of a variety of sources, but each one of them is contributing to the movie getting made. Respect that, and make sure always to keep everyone informed every step of the way. The more included everyone is, the less they will worry. This can be especially important during post when you may want to access some contingency money for enhancements. The better the communication throughout, the more likely it is that they will understand the reason behind your requests.
6. Screen the movie, collect feedback.
This is often a controversial issue, especially for directors. But I believe that, if handled the right way, screening a rough cut of the film in private, for friends and family and those you trust, before locking picture can help identify problems early on. If the majority of the audience flags something as an issue, then it is better to know that before the film is put in front of press and real audiences when you still have the opportunity to deal with it. I combine these screenings with a 1- or 2-page feedback form given out directly after the movie has finished and then collected before a verbal Q-and-A starts. I often advise directors not to answer questions, to just ask them and to listen to the feedback of the audience without defending his or her choices. These screenings are a tool for directors to get information. Be aware that often in the Q-and-A session there are one or two loud voices — so take very specific opinions with a grain of salt and instead look to the opinions of the group as a whole. Ask questions about what may be bothering you about the movie and keep them as non-leading as possible to get the most honest feedback.
Leaving music to the last minute is another common mistake. This includes both source music and score. Remember, a composer needs time to come up with themes and ideas, so including them in the screening of rough cuts can be useful. However, most composers (but certainly not all) like to compose to a locked movie. So if this is the case, allow proper time for them to work on the score between picture lock and the sound mix. With regard to source music, hiring a seasoned music supervisor is the key to clearing songs quickly. They can also make suggestions for your source cues so you run less of a risk of falling in love with temp music you put in that you can't afford to license. Remember, securing festival licenses without negotiating the full licenses is a risk, as somewhere down the line you’ll need to have the full rights for your music.
8. Don't give out DVDs of the rough cuts.
The main reason to be protective about giving out DVDs is piracy and trying to prevent an uncompleted version of the film from leaking. It is so easy for a movie to end up online now, so protecting any copies of the movie should be priority number one. People are not maliciously trying to sabotage your film, but no one will care about your movie like you do, and often movies get passed around and copied by assistants at agencies, etc., without them thinking about it. I destroy all DVDs that we need to screen and never let anyone keep a copy of the film. If someone needs to screen the movie (your sales agent, a publicist, an actor) then set up a screening for them — even if this means personally driving the DVD to their house and waiting two hours for them to watch it before bringing it back.