Organizing code is a core skill for software developers and as with all skills the most effective way to improve is to reflect on your previous choices and the fallout from them. There are a wide array of different strategies for organizing code and learning to recognize both the useful and the dangerous ones is very important.
Every two weeks I send out a newsletter containing lots of interesting stuff for the modern PHP developer. You can expect quick tips, links to interesting tutorials, opinions and packages. Want to learn the cool stuff? Then sign up now!