I do very little studio shooting, having a very small house and no studio. But sometimes I make the space (hey that’s not easy with 3 kids), and when I do, I almost always use a reflector with natural light, to mellow and/or direct the light into the subject. See for example, Impact Five-in-One Collapsible Reflector Kit.
For $39.95 today only, you can get a 5 X 7 foot black/white collapsible reflector at B&H. Reflectors come in a all sizes, from about a foot in diameter (useful in the field including with a flashlight at night) to huge). Backgrounds are also useful.
These images used a reflector for subtle fill light.