You are now ready to darken and lighten, i.e. burning and dodging.
Get a brush with a soft edge and not too high of an ‘opacity’ and put the FOREGROUND color on BLACK to darken/burn, and on WHITE to lighten/ get detail.
As the blending mode suggests this happens in a ‘soft’ fashion and lets you easily add a layer mask in order to get rid of some spots gradually and with full control.
© GraphicTutorials.net