It's commonly (sometimes famously) tried. But, it never seems to work. I've seen this arrangement up-close over many years. I've learned what to do, and what not to do. I'd like to offer 7 tips in getting this relationship to work. 1. Don't reinvent the wheel. When going into a new type of relationship like this, rely on as many established social formats as possible. Status report, project plans, and other seemingly mundane tools can help bring stability and familiarity to the new. 2. It's not a partnership. It's a client-vendor relationship. Someone, almost always the consultant, needs to be the client...and needs to be seen as the client. The client-vendor relationship is a very clear, very structured arrangement that makes immediate sense to all parties. 3. It's okay to disagree. Consultants and agency personnel have very different ways of working, ways of interacting with clients, and ways of seeing the world. These difference, when used well, 4. Be professional. No matter how many disagreements and diffrences, always stay professional. Sometimes consultants and agency folks tend to rankle each other. Stay above that. 5. Appoint ambassadors. Some agency people will understand consultants better, and vice versa. Let these people interact most and manage the relationship. On the other hand, some consultants don't like agencies, and vice versa. Let these people stay apart and work through the ambassadors. Not everyone has to be friends. 6. Keep the joint client's goal first. No matter what disagreements arise, it's the client who should benefit from the relationship. Keep that in mind when differences surface, and always ask "are we acting in the best interests of the client?". 7. Keep it win-win-win. Everyone, clients included, need to get something special out of the relationship. Don't neglect opportunities for fair rewards.