There isn't a «right» way to set up your light for a beauty shot. There are many.
Beauty shots can be done in natural light, with strobes and speed lights, reflectors and diffusors – often in combination with each other. The image above, was shot close to a large window with a speed light equipped with a large octa box as a fill light from behind. I could just as well used a reflector for the fill, but in this case the speed light was already in place. Anyway, it doesn't get much easier than this.
Clamshell setup
“My «go to» light setup for beauty shots used to be a clam shell lighting, though.”
My «go to» light setup for beauty shots used to be a clamshell lighting, though. In most cases I'd use a diffused beauty dish as my main light, coming in from the top straight in front of my model. Directly below, I'd place a silver reflector or a strobe in a soft box as a fill, to light up in the shadows. This simple setup will give you the standard beauty look often seen in commercials.
If you'd like to have a little bit of drama to your beauty shots, however, you need to add shadows. The image to the right was shot with a large parabolic soft box and nothing else. The size of the light modifier ensures that the light wraps nicely around the model. We didn't use a diffuser on the soft box, which had a sliver linning, to give the light a little punch.
Using strobes or speed lights with modifiers is perhaps the safest way to get a good result, as you are in charge of the light. But it's hard to compete with the quality of good natural light. That's why I try to work with natural light when it's available, at least for these kind of shots. The image below was taken in sunny weather in the shade of a tree without any other equipment than my camera and lens. All I needed was natures own good light.
