Director/Writer asking: Pitfalls to avoid in a truly collaborative D-W relationship?

Hey everyone,

I'm Marcus, a Director/Writer, and I'm tackling a new short film project right now. I've mostly worked solo, or in a traditional 'writer delivers script, director shoots' model, which has its own challenges. This time, I’m actively looking to build a more integrated, healthier collaboration with a writer from the ground up, moving past that hand-off stage.

My goal is for us to be building the story and vision together, almost simultaneously, to genuinely elevate the final product. I’ve tried informal brainstorming sessions and even shared early outlines, but it often feels like we're still just passing the ball back and forth, rather than playing on the same team.

For those of you who've successfully navigated this, especially early in your careers, what are the major pitfalls a beginner like me should actively avoid when trying to establish this deeper, more intertwined Director-Writer dynamic? What rookie mistakes kill that collaborative spirit?