As detailed as possible I'd say. If you can make it realistic then why don't do so?

I didn't really know how to answer this... I like skins with lots of hidden detail, as in usage of many very slightly different shades for colors. Not the kind of thing that you can make in any of the online skin editors.

I use GIMP to make skins like that.

But I also like it to feel simple, so no super huge contrasts and super complicated overlays.

I'll go for minnor details as I don't like them sooo overwhelming in little details, keep it simple and you'll win! :D

Are you referring to complexion of shading? 🤔