Or, better still, how to escape the taste trap. With the old rules in disarray, taste, like etiquette, has become a matter of individual choice--and all the more open to crass manipulation. Cannel counters the tricks of the home-decorating trade by helping the customer obtain, not special effects, but all-round satisfaction. Her few suggestions are simple and sensible: the living room should be comfortable (a commodious coffee table helps), the bathroom should be uncluttered, ""the foyer should make you happy you live there."" Then, department by department, she strips away the cant. Elaborately ""carved"" furniture may be molded plastic--and not necessarily the worse for it; ""original oils"" may be produced by human factory lines, original prints may be ""multiple originals,"" run off by the thousands; everything that tinkles is not true crystal. She'll also guide you through the snares of the Oriental rug market, alert you to the poor lighting (""a dark cave filled with too many lamps"") in most American homes, and, first and last, warn you away from buying household goods as investments. All to the end of developing the independent judgment that is, intrinsically, the basis of good taste.