In many projects I collaborate with people with other specialities and here are some important things to keep in mind:
As a group: have a clear goal in mind. Create a results-driven structure within your team that is appropriate for the goal you want to achieve. Give each member of the project a way to define his or her own role on the team. Establish a communication system. Seek consensus.
As an individual: create a collaborative climate. Be humble and open to others´ ideas and suggestions. Delegate tasks. Assume good faith.