Joakim Tornhill writes:
By request from FB groups, I have now done a huuge (anti Ian Hubert) course on Youtube that you can watch for free and learn how to make realistic material from scratch by following the progress on how to texture a lantern from that it looks brand new to like 50 years later and full of rust.
It's about 22(!) sessions going through techniques you can use and how to work with them in practice and also included common mistakes (and some minor that I also do) ... and how to solve them.
Good luck (and bring a lot of patience and free hours with you ;) )!
22 part playlist: