In principle, most conflicts are because of mismatched expectations. Where the expectations are really different the conflict can be really big. No one likes disappointment - when you think something is going to be one way and then it changes. The best prevention is a shared expectation of how things are going to be, who is going to do what, how things are going to work.
Practical Tip: Among two or more people with a shared task, figure out your shared expectations and write them down (or at least say them) so you can test your shared understanding. Contracts are shared expectations written down, so are ground rules and guidelines and bylaws. The process of writing these documents forces us to out our expectations and understand each other.
If you don't take time to discuss expectations with those you plan to depend on, best not to have any. - Craig Freshley