I would also mention "Emergent Design" along with KISS and YAGNI. Do not start your code base with a collection of design patterns. This is the usual cause of a

I would also mention "Emergent Design" along with KISS and YAGNI. Do not start your code base with a collection of design patterns. This is the usual cause of a complete over designed mess. Instead as the code grows look for the patterns to emerge and then apply them.