Mistreated scraped metal

I want to create a painted metal surface with peeled paint, some scratches, dirt, and rust.
I don’t have experience in doing complex maps and I don’t know if I should create different materials and mix them with a black and white image, or create one material with lots of maps to modify it, or maybe something else.
I would appreciate any ideas, or tutorial links.

There is a tutorial on painting this in your texture here:

great tutorial, thanks