Because LaTeX (and ultimately TeX) is only a macro-expansion system, the language does not impose any kind of good software engineering practice, program structure or coding style whatsoever on you. As a consequence, writing beautiful code (for some definition of “beautiful”) requires a lot of self-discipline from the programmer.
Maybe because in the LaTeX world, collaboration is not so widespread (most packages are single-authored), the idea of some LaTeX Coding Standards is not so pressing as with other programming languages. Some people may, and probably have, developed their own programming habits, but when it comes to the LaTeX world as a whole, the situation is close to anarchy.
Over the years, the permanent flow of personal development experiences contributed to shape my own taste in terms of coding style. The issues involved are numerous and their spectrum is very large: they range from simple code layout (formatting, indentation, naming schemes etc.), mid-level concerns such as modularity and encapsulation, to very high-level concerns like package interactionslash conflict management and even some rules for proper social behavior.
In this talk, I will report on all these experiences and describe what I think are good (or at least better) programming practices. I believe that such practices do help in terms of code readability, maintainability and extensibility, all key factors in software evolution. They help me, perhaps they will help you too.