Be nice to the crew.
One simple thing clients can do to make my life easier: Allow the crew to use your bathroom. You'd be surprised how many clients ask us to go to the nearest gas station or diner. Make the work environment comfortable. If it's 97 degrees, we're remodeling an attic, and the client won't let us turn on the AC — that's cruel. Also, maintain an air of diplomacy and good cheer. Wait 15 minutes before you discuss anything that's really upsetting you.