ALSO ALSO color corrective layers!!! Especially 'tone curve' and 'hue/saturation/luminosity'! For an average drawing i usually use around 2-4 corrective layers
WAIT i do actually have the old face saved cause i had made a duplicate of it when i did the hair. This is huge deal to me cause a small change like that, when the whole face is already rendered, would of taken me so long to fix and make it look seamless ;w;