Nothing new here, still just desaturating and adding color layers on top, with the layer set to multiply, or overlay, or hard or soft light, depending on which I think looks better. I tone the costumes with a combination of dodge and burn layers, airbrushing in lighter shades of color, etc. By the way, I rarely if ever use the eraser, airbrush, paintbrush or dodge/burn with the opacity of that tool set at 100%; usually its much lower, down in the 10-20% range. With the opacity that low, your less likely to see brush strokes.
