For me, the most important things in a house are the bathroom, dressing room, bedroom and study room. I have been paying attention to many architecture magazines and websites. It is amazing how you can create a spacious visual effect by utilizing different combinations of colors/materials and the arrangement of the furnitures.
I think one important element is the "open-space" design. Less clutters in sight naturally gives you a sense of openness and coziness. There is a good website where you can see many creative ideas about how to use space well. In case you are looking for inspirations for your own place, you can find it at Freshome.