It depends on the outer fabric you choose. For lighter fabrics I add padding between the outer fabric and the lining to give the bag support and body. Other materials, like fleece or minky fleece, are already thick fabrics. In those cases I don't add extra padding, both to keep that lovely softness and for technical reasons, because of the thickness under the sewing machine's presser foot.
The result is a more structured Beauty Case in the first case, and in the second a “fluffy” creation that's incredibly soft to the touch.