I am reading an article on this link, and in one part, it says 'patterns of thought and movement worn smooth with use'. I searched, and couldn't find a definition for 'wearing smooth'. Does it mean 'getting better'?
Your interpretation of it is quite close. In this case the writer is showing that he prefers to do things that he has done before.
"Patterns of thought worn smooth with use" is applying a physical descriptor to a non-physical thing.
However, he's using this as a positive, in the sense that rather than being destroyed, it has become comfortable, familiar, like a well-used path. So, in the end, he's just referring to methods of game play and game logic that he is already extremely familiar and comfortable with.