Paint, or more specifically its color, can help create the coziness your after. Here two different ways this can be done;
1) Use the wall color on the ceiling. This will help "pull down" the ceiling.
2) Use a slightly darker color on the ceiling. This works best if your walls are a light earth tone color. Use 1 shade darker (same color just a little darker) for the ceiling.
A warmer feel can be accomplished by using warm colors.