Rule of thirds
Derde-regelcompositie · Composition
Divide the frame into a 3×3 grid; place your subject at the intersections.
Not a sacred law, but a useful guideline. Put your horizon on the top or bottom line, not the middle. Place the face at an intersection, not a corner. And know when to break it: a centred, symmetrical portrait can be very powerful.
Tools that help with this: