I promised I'd do a tutorial, so here it is. It's mostly about layers and layer masks, and I didn't really elaborate on hue/saturation, brightness/contrast, levels, or color balance-- but you guys can figure those out, right?
Hope this was helpful to someone, because let's face it:
Making a tutorial is like presuming that I actually know something others don't, which is something I'm not so sure about . . . :icon_lol: