For the last couple of years I've been helping to write short films, and before that commercials, bumpers and the like. I've worked with a few writers and writer/directors, and I discovered something that, for me, really helps make it a successful collaborative effort. The secret is this:
Write to make it better, not to make it your own.
If you're a creative person, you're temptation is almost definitely to inject everything that you work on with your own personality and style. It's what makes your work unique. But when you're working to create as a part of a team, especially one where you're helping to support someone else's vision, the challenge becomes not doing that.
When I get a script or a treatment, and I feel the urge to make a change to it, I say to myself : “The person who wrote this is talented, and chooses his words carefully. With this change, am I trying to make it better, or just make something that feels more like my work?”
Once I know the answer to that, I know if I should include the note.