I like to use natural fabrics. Have you noticed while touching, that they are warmer than synthetic ones? Natural silk, cotton are «alive» and can be nicely draped into beautiful folds. It's good to work with them. Also it is pleasant to touch dolls that wear dresses made of natural fabrics.
I especially like Italian silk and velvet, Russian, German, French and Japanese cotton.
For the interior dolls, I often cannot find the right fabric - either the color is not the right one, or the drawing is not fine enough. Then I paint white silk myself using the batik technique.
I love using antique fabrics, tiny pieces bought at flea markets.