One area of collaboration involves knowing *where you are* in the decision making process.
There are three distinct phases that lead to a decision: Opening, Narrowing (aka Evaluating), and Closing. Usually, partners will be better at one or another of these phases.
In Opening, you are brainstorming, perhaps researching, thinking of all the things that could go into your project. This is the Dream Big Phase. In Narrowing, you and your collaborator evaluate the pile of information and pare it down to a manageable and attractive list of components. In Closing, you make final agreements based on your narrowed list. What will be included? What will be discarded?
If your partner is Closing while you are Opening, you see how problems will spring up. It’s helpful to make agreements about how you’ll tackle these three phases to avoid confusion and misunderstanding.