You can use this to quickly shade your skins like I do. This is a full version of this skin I made a while back. It seemed pretty popular, and there instructions on that post that I will copy paste here.

1. It's easy to use.
2. My personal process is importing the skin base to medibang and putting the "macro" as a secondary layer above it.
3. I select "Clipping" for the macro layer and then choose the effect of "Overlay" for it as well.
4. At this point, you might want to select the no-no areas and cut them out like face and ears.
5. Duplicate the layer as many times as you want or experiment with the different effects!

It's a lot easier than duplicating the same process over and over again.

Once you're done, you can export it back or save, then make small adjustments like any good skinner.