An interior design should communicate a feeling or some kind of message. With line you have so many ways to say something. Any lines you use should match the mood you are trying for. Take a look at how many things have lines – the carpet pattern? your Venetian blinds? Do they match the mood you want in the room? Look for unstable leaning lines in your home, like low ceiling slopes that make you feel uneasy. Visually support them with stable upright lines like a vertical wall covering , or a drape on a rod.