The word cinematic is often used for dark colours, grain or a wide crop. Those things can contribute to an atmosphere, but that is not what matters most to me.
A cinematic portrait feels as if something existed before the frame and will continue after it. Not everything is explained. The composition leaves some room.
Light and framing
I look at how light moves across a face or fur, where the shadow begins and how much surroundings the image needs. Sometimes a very tight portrait works. Sometimes deliberate empty space makes it stronger.
Those choices should support the subject. They are not effects for their own sake.
Not every image has to be dramatic
Cinematic does not mean every portrait needs to be dark or heavy. A bright interior, soft daylight or a simple studio setup can work just as well.
The relationship between light, posture and framing matters more than a recognisable visual trick.
An image with enough room
I want a portrait to suggest something without inventing a story that is not there. The subject remains real. The photography only shapes the way we look at it.