The easiest and fastest way to light beauty is place the light slightly above centre directly forward say 30º downwards, and add a reflector below centre angled to pick up light and redirect light from the main source to fill in shadows, yet at a reduced intensity.
By doing so you have a very safe way of ensuring a catchlight in the eyes, enough light to fill shadows , and avoid creating too much shape or volume.
That said, it’s time to avoid this boring old technique and pass on to a more personalised style.
First thing to do is raise the light higher. High enough to create depth under the nose, lips, and cheeks. Keep going until either the nose shadows starts to cross over the lips, or the catchlights in the eyes start to disappear. Now you are getting somewhere but it’s log from being finished. By raising the light you may have noticed you’re going to have more light on the top and decreasing (fall off) at or before the chine.
Two ways to fix this. One is to gobo the top edge of the light. Fast and efficient but sometimes impractical as the space is limited, weight if on a boom, or some other reason like the stand interfering.
The better way is to angle the light downwards,. This may not solve the hot spot , but will if you move the light away from the subject after.
Look again for the catchlights in the eyes, the shape of the shadow and where it falls.
You are almost there if you want front lighting. Just put a little fill reflector back in , as before but as not to kill the shadows move it higher and watch that it is not filling as much under the chin.
If what you are see is missing the volume you see in today’s best beauty photography , it’s because you need to have a direction to the light that creates volume , a unique and flattering volume for each person you shoot.
Move the same light off to both sides and keep it pointed towards the subject. For now this is still broad lighting as the light strikes the subject from the broad side and the shadows follow behind the light in the same direction ( away from the viewer).
When you find the best shadow, best jaw line, best cheek shape on which side it works the best you now have the most flattering side to shoot. As we haven’t yet turned the light towards the camera, this shape is something to watch for the pure form as it will change volume with the angle of the light creating a shadow not yet visible.
You’ll want to move the light far enough to create shape but not so far as to loose the shadow side catchlight! Nor do you want to fully shade the area under the ye, especially on women or you’ll have an excessively dramatic and masculine image.
Make sure you have the catchlights , not too much nose shadow ( really depends on nose shape), then move the light closer then farther away from the subject. You’ll instantly see huge differences in volume with the changes in light source size vs. relative distance to subject.
Last thing is to turn the light inwards, towards the camera until you feather the light away from the closest “hottest” spot or the brightest edge if you will.
Sometimes you’ll have to pull the light back towards the camera position to maintain the catchlights and not have excessive nose shadows when turning the light towards the camera for a somewhat short light.
This is the time to add or take away light. On a bright background to increase shadow strength you can add a black velvet on a board or a polystyrene black painted board. I find two or more 2” 4×8’ boards one side painted black with gaffers tape all around the edges the best compromise for studio photography. When I really want to take away light I pin a large black velvet onto the poly board. With a dark background you’ll want to maintain some detail in the darks areas. So the white side of a poly board will do, or a white boards like gator board, or even a flash onto a wall if you have large surfaces behind the camera.. One thing to be careful is when filling light, always remember the primary source direction and where your secondary light is . Avoid cross shadows and filling in all the volume you just worked hared on creating.
Another favourite is to add a small Fresnel just in front of the main light to create a sharp specular light but low enough power that it only defines the shadows and specular highlights without killing the main light’s volume and transitions.
The rest is just experimentation. I suggest starting out simple. When you know how to do the simplest way well, then start adding a light. Turning off a light, adding a kicker light from behind at an oblique angle, adding a strip light etc.