These are some materials I have been working on in Substance Designer, these are all 100% procedural.
Leather - This substance will procedurally scuff parts of the texture based on the heightmap, you can control the spread and intensity of the scuffing.
For this substance, I created a brick generator substance, that I could use to create infinite brick variations. I then used an FX node to place the bricks. I also created a crack generator that can be re-used in other substances.