Edge refinement is as critical to making the initial selection as remove background photoshop . When the subject is placed on a new background, then rough outlines, halos, and background pixels that are still present can be visible. You can use Photoshop's Select and Mask workspace to adjust edges as needed, and manual masking using white foregrounds and black backgrounds allows you to make precise corrections to areas with detail. Visuals Clipping recommends zooming in for final cleanup and comparing the subject to both the light and dark backgrounds to look for unwanted edge artifacts.