ah yes, its pretty good for generic material, there is no painting in it, but the use of filters and layer styles is used heavily, so its pretty good for starting out.
i find it helps to work at large resolutions, so you can draw fine details which you would struggle to do with small amount of pixels, so you can let the scaling sort it out at the end
my basic workflow is to just start with a solid colour layer, then create dodge and burn layers on top of it, aswell as any pattern overlays etc. it usually ends with alot of layers
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