There's more to choosing a new rug than just picking a pattern you like. Think in terms of balancing function and style, and you'll have an easier time finding a rug that will work for you.
The room where you put your rug will help determine its placement within the room, which will then affect room's look, feel and functionality. If you're putting an area rug in your living room, make sure it's large enough to fit under the front legs of all furniture situated around it, and leave 12-18 inches of exposed floor around the edges. In the dining room, a rug placed under the table should extend beyond the chairs when they're pulled out. For the bedroom, choose a large plush rug and place it under the bed to create a warm greeting for bare feet. Long, narrow runners work well in hallways. Always leave several inches of exposed floor on either side of the runner.
Choose a rug with a weave that fits your lifestyle and taste. Tufted rugs have a soft feel and plush exterior and are machine washable and backed with skid-resistant material. Woven rugs tend to be more expensive but also more durable, and some require professional cleaning. Flat weave rugs have a flat, thin pile and can be layered for extra padding.