Communication! So you never have to worry about the state of the work.
You shouldn't get nervous because an artist goes quiet for long stretches of time and doesn't send work-in-progress pieces. I believe in both sides having a clear understanding of deadlines and project direction.
Picture: The old man got tired of living among his peers. He heard about a place. A place where all living things entering its realm got forgotten from the world. "What a chance !" he thought. Little did he know about the terrors in these woods ! Bears the size of a house ! Water bears you could ride ! So far he managed, but for how long ?