To minimize the appearance of a double chin in photos, extend your chin slightly forward towards the camera while optionally tilting your upper body towards the camera as well.
This technique helps to tighten the skin under your chin and create a more defined jawline. By bringing your chin forward, you stretch the neck and reduce the appearance of sagging skin. Tilting your upper body slightly forward can further enhance this effect. Remember not to overdo it – a subtle adjustment is usually all that's needed for a natural and flattering look.