UV unwrap guidelines and best practices?

Support Materials and Textures
1

Since I think uv unwrap is one of my weakness , I’ve been searching for tutorials and guidelines to unwrap correctly , but My search has been unlucky.
Do you have some tutorials /video to share, pls?

2

https://www.google.com/search?q=how+to+uv+unwrap&oq=how+to+uv+unwrap&aqs=chrome..69i57.4679j0j4&sourceid=chrome&ie=UTF-8#q=how+to+uv+unwrap&safe=off&tbm=vid

https://www.google.com/search?q=how+to+uv+unwrap&oq=how+to+uv+unwrap&aqs=chrome..69i57.4679j0j4&sourceid=chrome&ie=UTF-8#safe=off&tbm=vid&q=uv+unwrapping