Have people you trust at hand
One of the best tools you can have in completing a film is a test audience. Before you bring your film out to the public, it's a good idea to have more private feedback. Typically this is going to be your story producer or the director, but in most instances they've been working as long as you have on the film, are going to be just as close to the story as you, and are likely to be blind to a number of the same issues. It's always good to have a friend or two that knows the business and is willing to give honest feedback about their experience watching the film.
It's important to make sure that this friend isn't going to be a "yes"-man; you're not looking for someone to blindly tell you that your efforts are valiant and that your film is the best thing since Citizen Kane. You need someone who can point out what's working and what isn't, and in the best case scenario, offer some clues as to how you can communicate, visually or otherwise, what is missing from your current edit.
Having someone who works professionally in the film industry to give you feedback is very helpful, but anybody with a healthy sense of reflection and cinematic knowledge can be helpful. Just make sure that you choose people whom you trust to give feedback (even negative feedback) in a fitting manner. Positive notes can help move a film in the right direction just as quickly as poorly constructed feedback can derail you. Besides, filmmaking is an incredibly lonely and difficult process, it's nice to introduce outside company once and a while. Doing it all in a vacuum will not only damage your film but is a sure way to land yourself in the nut house. Trust me on this one.
Golden rule of editing
If it were possible to boil everything down to a single slogan or rule, it would be something that my Thesis Advisor always told me when I was heading into the cutting room: "Stop thinking about it, if the damn cut works, it works." This sounds like very common sense, but all too often when you find yourself in the weeds it can be very refreshing advice. My friend and often co-filmmaker Keif Roberts equally reminds me to avoid "paralysis through over analysis," or "don't over think it!" which I find to echo this mentality.
Whether you agree or disagree, I think that this sums up a good portion of my editing philosophy at the moment, and I believe they equally relate to both narrative and documentary.
These tips are intentionally broad, and are meant to act as more of a background process in your mind when you're visiting your film's material. A little kindle to your creative fire.
What's been going through your mind while you've been editing your stuff? Share your thoughts and experiences in the comments section!