It takes practice, both for you
and for the people around you.

*chuckle* One year, we had a
housemate AND other random friends
often dropping by during summer,
which happens to be my busy season for writing -- I do calendar/almanac assignments then. I actually took one of those foam doorknob signs, with a tiny whiteboard on it, and wrote "The Dragon Is Writing." I would hang it on my office door so that people would know not to bother me. (I wasn't closing the door for air circulation reasons.) It saved many arguments.