I was talking to a friend of mine recently that regularly engages creative and digital agencies. He has worked in client and agency roles. He had an interesting observation from a client perspective:
"I know too much about the agency process", he explained. "I know that fighting for internal agency resources is hard. That my account manager is likely to change a few times during the project. That I'm not your only client. And that there will be scope creep. So let's all just be open and honest about it."
Great advice.