THERE'S a way to make every meal better, according to Helmut Schonwalder -- add a nicely folded napkin. "The napkin makes all the difference," said Mr. Schonwalder, who has developed dozens of napkin folds. "It creates atmosphere, and it cheers people up. They say, 'How did he make this?' " His Web site (schonwalder.com /Napkin_Folds/napkin101.htm) explains how. It gives step-by-step instructions for making four dozen of his napkin folds, which he has developed during a career in the hotel and restaurant industry.