One of the easiest ways to add warmth to any space is through the use of sheepskin throws. Either casually tossed over a chair or placed on the floor these little throws do wonders for a room. I threw one over a chair in my living room and haven't thought about the hideous cushion hiding underneath once since then. How easy!
The best part? They are extremely easy to find. Ikea sells a version (though you generally have to dig around a bit in person to find a good looking one) and Design Within Reach has some really lovely ones as well.