>>2225569I'd offer different advice than
>>2225569.
Enlarge the girl (the center of interest) but she's already clipped on one side, so it's not necessary to crop elsewhere.
As a general rule, too much "symmetry" is boring. Leonardo's "man in a circle" is great for demonstrating anatomy and proportions but you wouldn't paint a portrait that way.
Better to have the subject off-center. Look up "rule of thirds" in drawing and photography.
>>2225573 is a good example.
Given a choice, have humans facing towards the center of the image. That gives the impression they're looking at the viewer. Eye-contact adds human interest.
In this particular case, because the girl is shaded with screen-tones, I added some subtle procedural texture to the background. Just enough to keep the eye from skidding around, hunting for relief from blandness, and not enough to distract from her.
As noted, these are general rules. Every image is unique and there are times to defy them if you feel it looks better.
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