Basic rules of house decorating can be strictly followed, or totally open to personal taste and interpretation.
However, one basic rule is to consider the locality and architecture of a home before developing a decorating design plan. A southwestern motif might be totally out of place in a New England Cape Cod style home, and vice versa for an adobe home in the desert Southwest.
Room use also is important to overall design. In the kitchen, for instance, the inclusion of the work triangle is critical for ease of movement and convenience. Regardless of room style and décor.
But since the bottom line is that the homeowner is the one who needs to be happy with end results and live in their design environment, any successful design needs to be open to personal taste and expression.
In the final analysis, interior design is an art. The room being decorated becomes the canvas. And for the most part, the homeowner is the artist.