Marker practice! I traced a photo in Procreate to map out where the shadows were, then printed a copy to trace onto my good marker paper. IDK if I'm just using my gray markers much more than the others but I was having some problems with one of my middle grays drying out, and they weren't giving me the contrast I was expecting, so I tried the version with greens (and a light blue, because I didn't have a light enough green) to see if I could at least get blending I was happy with.