Why do people look so blank, so vacant, so unnatural in portraits? Peter Hurley, a leading head-shot artist for actors, celebrities and executives, said people look like badly embalmed cadavers because they try to pose, but lack the skill to look natural doing it. Even professional models, experts at a certain haughty look, seldom know how to look natural. “I have to deprogram them into something that is more real,” said Mr. Hurley.

How does Mr. Hurley get the personality to shine through in a flattering way? Here are some of his top tips from those offered in his instructional video, “The Art Behind the Headshot.”

Keep your chin up. People have a tendency to tuck their chins in photos, creating an unflattering neck wattle. The simple way to fix it, said Mr. Hurley, is “bring your forehead toward the camera.” From the side it looks like they are doing an E.T. imitation, but from the front it cleans up the neck and jaw line.

The trick is to get the subject comfortable with the unnatural posture. Mr. Hurley often shows subject their before and after forehead forward shot with the encouragement, “Feels weird, looks good — just go with it.” For shots from the side he instructs, “Bring your ear toward the camera.”

Show your good side. People’s faces aren’t perfectly symmetrical and one side usually photographs better than the other. How do you find the good side? Most people subconsciously find it for you by parting their hair on their good side, said Mr. Hurley. Most people also have one eye that is larger than the other. To even them out, ask the subject to turn three quarters of the way toward the camera with the larger eye further away. “I usually put the small eye in front and drop the head down, so they look up and it opens it up,” said Mr. Hurley.

Get your Eastwood on. Mr. Hurley said that people always look better when they squint slightly. The crucial word is slightly – not a pained expression as if reading fine print. The real trick is to squint with the lower lids only – think of the expression Clint Eastwood makes when assessing Lee Van Cleef before a showdown. “In my opinion, fear and uncertainly comes from the eyes,” Mr. Hurley said. “If someone wants to look confident, have them squint.”

Have a laugh. Most people tend to have a fake grin, with pursed lips, or they squeeze the mouth tightly as if trying to keep a secret from escaping. Mr. Hurley’s goal is to get his subjects looking confident but approachable. “I will tell them to allow a little space between their lips,” he said, just enough to breathe. “The mouth is where all of the approachability comes from.”

To get a range of expressions he will give non-sequitur directions. “I like throwing things from left field. I like to say ‘look perplexed,’ which they try, it gets a laugh and it’s usually good.” In fact, it doesn’t matter what you discuss, as long as it makes the subject less self-conscious. “People can’t think about how messed up their mouth is if you are asking about the score of the game last night.”

Frame it up. The most important visual element of a good head shot is the eyes. Mr. Hurley frames his subjects to the rule of thirds. That rule of composition means if you were to draw a tic-tac-toe board on your finished photo, the major elements would be on one of the lines or intersections. Mr. Hurley gets in close enough that the top of the subject’s head is often out of the frame. “If I want the top of the head,” he said, “I shoot more of the chest so the eyes are still one third from the top.

In the end, it comes down to learning how to make people comfortable positioned in a way that feels uncomfortable. “I’m 90 percent therapist, 10 percent photographer” said Mr. Hurley. If all else fails to get a pleasant expression, “I say, ‘Don’t look so miserable,’” he said.” “If they don’t smile at that, you have a serious problem on your hands.”