
When you are changing lighting setups or camera settings you are not able to pay attention to expressions. Trying to give a lot of variety with lighting setups may not be the best approach.
KISS – Keep It Simple Stupid
It takes a lot more skill to get great face expressions than it takes to change a lighting setup. You have to build trust with the person. You have to have a connection with them so that together you can capture the true essence of the subject.

I do super minor lighting changes so that I can spend more time on getting lots of expressions.
One thing I do with my setup is just change the background from a grey to a white background.

I can pause just for a moment and turn on or off the two lights behind my white muslin background. Off I get a nice neutral grey. The light from the beauty dish is what is lighting the background and my subject.
When I have my background lights on they are giving me one stop more light than I have set on the subject. This gives me a really clean white background.

I love to shoot 50 to 100 images before I change the background.

I encourage people to bring a couple of outfits. It is amazing to me how much wardrobe change impacts the final photo.

Changing from a low-key photo to a high-key photo also can help change the mood of the photo.

My tip is to pick one outfit and shoot a lot. Go for 100 photos without changing lighting. background or clothing. Then just change the background and repeat. After you have done that, then change outfits and shoot again.
Make the emphasis of the portrait/headshot session about getting an expression. Go past the extremes of sadness and joy. Then try and shoot all the nuances of expressions.

Don’t forget to get verticals and horizontal photos.

Most of all remember the thing that makes a great headshot is EXPRESSION!!!

It is much easier to get a pleasant and real expression if you have pushed the limits of expressions first.
