How would you make your house feel cozy besides using pillows and books?

Maybe it’s just me. But with a lot of tile flooring, dark tile countertops and scant sunlight coming in the house is not as cozy as I’d like. With the bedrooms it’s a lot easier because I have nice quilts and they’re carpeted. But how should I make the the dining room, den and living rooms cozy? The living room has a gas fireplace so it’s all black inside and we never use it.