thanks for your eyes, guys.
calling this done... for a while at least.
but still taking c+c.

try experimenting with an off center light, or directly overhead, even under lit for scary effect (clowns = scary)
basically anything other than this front lit source which creates "pillow shading" and will make some cry.
personally i feel i have been wrestling with some things about color.
i found "hue shifting" to be interesting and helpful.
i think i like the flesh tones you picked, but you could probably go with more drastically shifted ramps overall.

your piece, for the benefit of the readers:


i am doing arm anatomy too now.
your muscles are reasonable, but the shading is really limited with only high, mid, and shadow.
try another tone in the ramp and define the volumes more with chunks of shapes, and less with pure lines.
even if this is strictly a muscle exercise, i advise that a full composition will still give you more growth than isolating one thing.

isometric dog monsters are real, and this is how they realy walk/lumber
i checked.
sorry for the misunderstanding.