The thing that has always guided me right is that you need to a) split up functions, b) document method headers in every case with a short description of what i

The thing that has always guided me right is that you need to a) split up functions, b) document method headers in every case with a short description of what it does, and finally c) come back one month later and rewrite any documentation that does not make sense. This is the most important step. If you cannot remember it from a blank slate, then no one can. Keep doing that until you understand the code at first glance. Then your code will be easy for anyone to maintain.