I usually wear light blue dress shirt no tie, name tag, grey slacks. It's a 'uniform' I've put together over the years. I think it's effective. I top it off with a burgundy baseball cap, often Oklahoma University (!). I think most people think I'm a postal carrier, fedex or meter reader. When they open the door, they get Friendly Funeral Director! Oh no!
First time I heard of anyone wearing a baseball cap on calls.