Professional headshots are about making a connection with the viewer. It's the same for business headshots or acting headshots. Your expression should evoke confidence and warmth. You should appear warm and engaging. A great headshot says to the business manager or casting director, “You can trust me to fill the role you have to offer.”
How to make your professional headshot better?
Practice! Sounds strange but that's how you get better at anything. Stand in front of the mirror and practice expression. The number one problem with headshot sessions is discomfort. The common element to any great headshot is confidence. What betrays that is insecurity. What overcomes insecurity is getting comfortable with yourself. So look yourself in the eye everyday. Practice a subtle closed mouth smile and an open mouth smile. A slight narrowing of the eyes from the cheeks up can add warmth and sincerity. Yet the so called “squinch” doesn't always work and requires warmth conveyed through the mouth. Otherwise it reads as consternation.
What to wear for your headshot.
Simple clean lines is the key to clothing in a headshot. For men this is very easy. Don't wear heavily patterned ties. Solid and muted colors are best.
Women have more choices. For this reason I have an abundance of cautions for them. Keep in mind your headshot should be about your face and your clothing shouldn't distract from your face.
Don't wear puffy sleeves. Puffy sleeves take up more room in the frame and add size. You will look wider especially with a headshot cropped photo. Same is true of frilly seams.
Do wear sleeves. I would always recommend sleeves over bare shoulders even if you have great arms. I think it makes for a better crop in a headshot.
If a jacket wear one with seam lines that form a V with the width of the V at your neck.
Do not wear pleated necklines, draped necklines, plunging necklines, necklines with frills, or seams that have frills. Seams should be a simple clean line.
The simpler and cleaner the seam line the thinner you will look. If you try to hide weight with clothing for a headshot it's usually a diminishing return. Your best bet is a shirt or dress with a vertical line intersecting the bottom crop. Make sure the seam on your jacket and shirt lays flat and doesn't strain.