thanks for joining in jon !
your concrete could well be used for entrance steps or the like and the lizard skin you could try on marty, frank's chameleon in the examples folder.
i see you use the turbulence a lot, try and play with the octave, lacunarity and gain settings, the default ones are rather odd.
now this is the decorated pig thread created by meshman, this means there is no incentive at all to create any remotely usable or realistic material, it's about pure fun exploring the vast possibilities of awkward node combinations, trying to come up with weird but impressive patterns.
going through this joyful experience you will learn more than attempting to mimic realism, the skills for that will come on the fly.
have fun and come back with more,
- archie