Don’t forget you can use external programs to create a complex base texture at high resolution (i.e. marble), and then use cycles procedurals to do trickery to the coordinates to apply it as tiles (or seamless in some cases) where obvious texture repetition (CGI giveaway) is significantly camouflaged.
Tiled example:
Custom box mapped example (non-tiled):
Closeup of the latter:
Maintaining this kind of detail would require way higher res textures than I can afford. The structure of the texture (other software are way better as they support seamless generators - cycles ones are garbage sorry to say :() dictates what kind of manipulations I can do to it; position lookup only, uniform or non-uniform scale variations, rotation variations (typically not on wood grains that are directional).
External is way better than Blender (as far as pure texture painting goes), but don’t lock yourself into a mindset.