Look at the grain in real light, then zoom in to the pixels. The bumps that catch the light and shadow create the sense of depth. If a bump only changes the color slightly and doesn’t affect shadowing, it’s fluff. I’ll flag the spots that throw a shadow or have a visible texture edge. Then I paint those by hand, adding a subtle dirt rim on the peaks—because pure realism feels dull. I’ll add one “wrong” bump here and there, just to see if anyone notices, and if they do, I’ll tweak it back. That’s how I decide.